U.S. patent application number 12/803637 was filed with the patent office on 2011-01-27 for mobile router stack.
Invention is credited to John C. Fulknier, Brian J. Smith.
Application Number | 20110019651 12/803637 |
Document ID | / |
Family ID | 46326999 |
Filed Date | 2011-01-27 |
United States Patent
Application |
20110019651 |
Kind Code |
A1 |
Fulknier; John C. ; et
al. |
January 27, 2011 |
Mobile router stack
Abstract
A wireless mobile router stack (400) includes a plurality of
network controllers (142) communicating over a local area network.
Each network controller includes a CPU (222), with and one or more
local area network interface devices (146, 148, 333, 360) and one
or more cellular network interface devices (202, 204, 206) in
communication with the CPU. At least one of the local area network
interface devices hosts client devices on a wire (333) or wireless
(170, 180) local area network. All of the cellular network
interface devices connect to a host cellular network (110) as a
client when an appropriately configured cellular network access
point (112, 114, 116) is available. At least one of the network
controllers operates to route traffic between locally reachable
devices and non-locally reachable IP address over a plurality of
the cellular network interface devices.
Inventors: |
Fulknier; John C.; (Allston,
MA) ; Smith; Brian J.; (Somerville, MA) |
Correspondence
Address: |
Edward L. Kelley;DBA Invention Management Associates
5 Utica Street
Lexington
MA
02420
US
|
Family ID: |
46326999 |
Appl. No.: |
12/803637 |
Filed: |
July 1, 2010 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11650634 |
Jan 6, 2007 |
7778230 |
|
|
12803637 |
|
|
|
|
11497892 |
Aug 2, 2006 |
7813314 |
|
|
11650634 |
|
|
|
|
60595747 |
Aug 2, 2005 |
|
|
|
Current U.S.
Class: |
370/338 |
Current CPC
Class: |
H04L 45/60 20130101;
H04L 45/00 20130101 |
Class at
Publication: |
370/338 |
International
Class: |
H04W 84/02 20090101
H04W084/02 |
Claims
1. A wireless network router stack comprising: a plurality of
network controllers each comprising a CPU, a memory module
associated with the CPU, a cellular network interface device and a
local area network interface device each in communication with the
CPU and at least one additional cellular network interface device
mounted on one of the network controllers in communication with the
controller CPU; wherein each of the cellular network interface
devices is configured to become a client of a cellular network;
wherein at least one of the local area network interface devices is
configured to host locally reachable local area network configured
client devices; wherein each of the plurality of network
controllers is configured to exchange network signals with each of
the other of the plurality of network controllers over the local
area network interface devices; program steps operating on at least
one of the network controllers for routing network traffic between
the locally reachable client devices and non-locally reachable
network IP addresses over any one of the cellular network interface
devices.
2. The wireless network router of claim 1 each of the plurality of
network controllers is configured to communicate with each of the
other of the plurality of network controllers using a Mobile ad-hoc
network (MANET).
3. The wireless network router of claim 1 each of the plurality of
network controllers is configured to communicate with each of the
other of the plurality of network controllers using a mesh
network.
4. The wireless network router of claim 1 each of the plurality of
network controllers is configured to communicate with each of the
other of the plurality of network controllers using one of WiFi,
Bluetooth, ZigBee, and Ultra Wide network communication
standards.
5. The wireless network router of claim 1 each of the plurality of
network controllers is configured to communicate with each of the
other of the plurality of network controllers over a wire local
area network (LAN).
6. The wireless network router of claim 1 each of the plurality of
network controllers is configured to communicate with each of the
other of the plurality of network controllers over a combination of
wire local area network (LAN) connections and wireless local area
network (WLAN) connections.
7. The wireless network router of claim 1 wherein the local area
network for hosting locally reachable local area network configured
client devices comprises a plurality of local area networks
operating on a plurality of different local area network
communication standards.
8. The wireless network router of claim 1 wherein-each of the
plurality of controllers is housed within an enclosure further
comprising: an I/O interface passing through the enclosure that
includes one or more antenna ports; an external antenna connected
to each of the cellular network interface devices mounted on the
controller through the one or more antenna ports.
9. The wireless network router of claim 1 further comprising: a
satellite telecommunications network interface device disposed on
one of the network controllers in communication with the controller
CPU; program steps operating on at least one of the network
controllers for routing network traffic between locally reachable
client devices and non-locally reachable network IP addresses over
the satellite telecommunications network interface device.
10. A network operating method comprising the steps of: configuring
a plurality of network controllers with a controller CPU, a
cellular network interface device in communication with the
controller CPU, with and a local area, network interface device in
communication with the CPU and with at least one additional
cellular networking interface device mounted on one of the
plurality of network controllers and in communication with the
controller CPU; forming a local area network that includes all of
the plurality of network controllers; forming a local area network
for hosting locally reachable local area network configured client
devices thereon; routing network traffic between the locally
reachable client devices and non-locally reachable network IP
addresses over any one of the cellular network interface
devices.
11. The network operating method of claim 10 wherein the routing
step comprises simultaneously routing the network traffic over a
plurality of the cellular network interface devices.
12. The network operating method of claim 11 wherein each of the
cellular network interface devices is substantially identical
further comprising the steps of: establishing a plurality of the
cellular network interface devices as a client on the same cellular
network; simultaneously routing the network traffic to the
non-locally reachable network IP addresses over different client
devices of the same cellular network.
13. The network operating method of claim 11 wherein the cellular
network interface devices include cellular network interface
devices configured to become clients of different cellular network
types further comprising the steps of: establishing the cellular
network interface devices as clients on a plurality of different
cellular network types; simultaneously routing the network traffic
to non-locally reachable network IP addresses over clients devices
of different cellular network types.
14. The network operating method of claim 11 further comprising the
steps of: determining cellular network operating parameters for
cellular networks that are hosting cellular network interface
devices included on the plurality of network controller; routing
the network traffic to non-locally reachable network IP addresses
over cellular network interface devices that provide the most
favorable cellular network operating parameters.
15. The network operating method of claim 14 wherein the step of
determining cellular network operating parameters comprises one of:
determining a signal strength at each cellular network interface
device; determining a bandwidth capacity over each cellular network
interface device; determining a response time over each cellular
network interface device.
16. The network operating method of claim 10 wherein an outgoing
data packet originating from any one of the other locally reachable
devices includes a locally reachable source IP address and a
destination IP address and wherein each of the plurality of
cellular network interface devices that is established as a client
on a cellular network is assigned an IP address further comprising
the steps of: determining if the destination IP address of the
outgoing data packet is locally reachable and if not; selecting a
cellular network interface device associated with one of the
network controllers to route the outgoing data packet to the
destination IP address over; translating the outgoing data packet
to replace the locally reachable source IP address with the IP
address assigned to the selected cellular network interface
device.
17. The network method of claim 10 wherein the step of forming the
local area network that includes the plurality of network
controllers comprises forming a mobile ad-hoc network (MANET).
18. The network method of claim 10 wherein the step of forming the
local area network that includes the plurality of network
controllers comprises forming a mesh network.
19. The network method of claim 10 wherein the step of forming the
local area network that includes the plurality of network
controllers comprises forming wire and wireless local area network
connections.
20. The network method of claim 10 further comprising the step of
configuring all of the network controllers with a plurality of
cellular networking interface devices in communication with the
controller CPU.
Description
CROSS REFERENCE TO PRIOR APPLICATIONS
[0001] This application is a continuation of application Ser. No.
11/650,634 entitled MOBILE ROUTER DEVICE, filed Jan. 6, 2007, which
is a continuation-in-part of application Ser. No. 11/497,892
entitled MOBILE ROUTER DEVICE, filed Aug. 2, 2006 and claims
priority under 35 U.S.C. 119(e) to Provisional Application Ser. No.
60/595747, entitled INTERNET MOBILE ROUTER DEVICE, filed Aug. 2,
2005, each of which are incorporated herein by reference in their
entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a mobile network router
that provides a network interface between locally reachable devices
and a cellular network. In particular, the present invention
relates to a plurality of mobile network routers stacked together
and configured to establish a plurality of network connections with
a cellular network.
[0004] 2. Description of the Related Art
[0005] Mobile computer and other mobile electronic device users are
increasingly relying on continuous access to Wide Area Networks;
(WAN's), such as the world wide web, (www), Internet, Intranets,
etc. to access data and software tools and to remain in continuous
communication with others, e.g. by email, instant message,
telephone, etc. Recently, wireless communication systems utilizing
designated radio frequency bands have allowed mobile devices to
interconnect with a WAN or the Internet whenever the mobile device
is within the usable range of a compatible wireless network.
[0006] Conventional wireless local area networks, (WLAN) are often
deployed inside structures such as homes, offices and public and
commercial buildings for networking with client mobile computers
and other client mobile electronic devices. In addition, larger
wireless network deployment over a campus or city are also known to
network with a large number of client mobile computers and other
client mobile electronic devices. Generally a wireless network
deployed over a usable range includes a wire network interface to a
WAN e.g. through an internet server and Internet Service Provider,
(ISP). In these wireless networked areas a client device can
usually access a WAN or the Internet through the wire network
interface and may have continuous access to the WAN or Internet as
needed as long as the client device remains within the usable range
of the wireless network.
[0007] A typical problem faded by the average WLAN configured
client device user is that when the client device leaves a WLAN
zone, the client device can not communicate with a network to
access network services. This problem has been addressed by
cellular network providers and specifically by commercial cellular
telephone service providers by providing cell phones and PDA's with
access to a WAN or the Internet over a cellular network and by
equipping cell phones and PDA's with basic email and web content
display and editing functionality. However cell phones and PDA's
are not equipped to perform even routine computer tasks and most
portable computers are not equipped with cellular network
interfacing gear. Accordingly, there is still a need to provide WAN
or Internet access to mobile users wishing to perform routine
computer tasks in places where network access is not available,
e.g. when traveling in a vehicle, watercraft or aircraft or when
traveling for work or pleasure.
[0008] Generally, cellular networks provide broad or global
coverage areas and provide WAN and Internet access and other
services to cellular configured client devices. However, there is
no convenient way for a WLAN configured client device, e.g. a lap
top computer or other portable electronic device to access a
cellular network and take advantage of the services provided by the
cellular network.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention solves the problems of the prior art
by providing a stack of wireless network routers (402, 404, 406,
408) interconnected by a local area network connection. The local
area network connection may comprise a wire or a wireless network
connection including a host client arrangement or a Mobile ad-hoc
Network (MANET), peer to peer, (P2P) or a mesh network arrangement
formed by local area network interface devices mounted on each of
the wireless network routers with each network router (402, 404,
406, 408) including a local area network device in communication
with the mobile router CPU. Each mobile router (402, 404, 406, 408)
further includes a cellular network interface device (316) in
communication with the CPU (222) and each cellular network
interface device is configured to become a client of a cellular
network, whenever a compatibly configured cellular network access
point is available. In addition, at least one of the mobile routers
(402, 404, 406, 408) and preferably all of the mobile routers (402,
404, 406, 408) includes a plurality of cellular network interface
devices in communication with the local CPU (222). The router stack
operates to route network traffic originating from locally
reachable devices to non-locally reachable destination IP address
over a plurality of cellular network interface devices
simultaneously. Moreover, the plurality of cellular network
interface devices may reside on a single mobile or may reside on a
plurality of mobile routers. In addition, the mobile router stack
may include a plurality cellular network interface device types for
simultaneously becoming a client of a plurality of cellular network
types.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The features of the present invention will best be
understood from a detailed description of the invention and a
preferred embodiment thereof selected for the purposes of
illustration and shown in the accompanying drawing in which:
[0011] FIG. 1 illustrates a schematic representation of one example
of a network environment including a mobile router according to the
present invention;
[0012] FIG. 2 illustrates a schematic representation of one example
of a mobile router according to the present invention;
[0013] FIG. 3 illustrates a schematic representation of a preferred
mobile router configuration according to one aspect of the present
invention;
[0014] FIG. 4 illustrates a schematic representation of a stack of
mobile routers configured according to another aspect of the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Turning to FIG. 1, one example of a wireless network
environment is shown schematically. The network environment
includes a wide area network WAN 100, such as the Internet. The WAN
generally comprises a plurality of network devices 102, e.g.
servers, digital data storage devices, telephone switching gear and
network traffic controllers, all interconnected by a wire and
sometimes wireless, e.g., microwave, infrastructure 104, such as
the world wide web, (www), and other global telecommunications
infrastructures. The WAN network 100 comprises a host to many
network clients with each network client having a unique network ID
such as an Internet Protocol Address, (IP Address), a Uniform
Resource Locator, (URL), an email address, a telephone number
etc.
[0016] Generally communication signals passed over the WAN network
100 include, digital and analog electrical signals generally
transmitted through the network infrastructure and generally being
communicated from one specific client device to another or from one
client device to many specific client devices. The digital and
analog signals may include a telephone call between two users, an
email sent from one client device to one or more other client
devices or a client browser request to access to a particular
server or network client device to exchange data files there
between.
[0017] Generally, network interface elements are included local to
or incorporated within each client device. In addition, the WAN 100
and infrastructure 104 includes various network interface elements
such as switches, hubs, routers etc. Network interface elements are
used to format network signals, to associate a network address to a
client device network, and generally to allow network signals to be
exchanged between client devices of many types and configurations.
A common wire network interface element is the Ethernet interface
module installed in many client devices. An Ethernet interface
module generally operates according to the IEEE standard 802.3 to
divide data into frames or packets and format the frames according
to a communication protocol such as the Transmission Control
Internet Protocol, (TCP/IP). Of course other wire network interface
device types are also in use and usable with the present
invention.
[0018] In addition, the WAN 100 includes network control elements
configured to interface with the infrastructure 104 and with other
host networks, to direct network traffic, to control access to the
network, to measure network parameters etc. Typical WAN network
control elements comprise network servers configured to establish a
host/client relationship with many thousands of client devices and
to manage signal exchanges there between.
[0019] The network environment also includes a cellular network,
generally 110. The cellular network 110 comprises a plurality of
wireless network access points, 112, 114, 116 configured as radio
transceivers. In the example of FIG. 1, a first access point
comprises a base station 112. Generally the base station 112 is in
communication with a cellular network controller or router 118. The
network controller 118 may comprise a computer or server positioned
local to the base station 112 and connected to the WAN 100 via a
wire or microwave link. Alternately, the base station 112 may be
connected to the WAN via a wire or microwave link and the network
controller or router 118 may reside anywhere on the WAN 100. In
addition, each cellular access point 112, 114, 116 exchanges
wireless signals with other cellular access points to communicate
with the base station 112 and network controller 118.
[0020] The cellular network controller 118 controls communication
traffic on the cellular network. In particular, the cellular
network is a host network having a plurality of client devices. The
cellular network controller 118 controls the network traffic to
each client device and may provide different network services to
different client devices. In addition, the cellular network
controller 118 may provide a cellular network client device with
access to the WAN 100.
[0021] Generally, cellular network access points 112, 114, 116,
(cell towers), comprise one or more radio transceivers, usually
elevated above the ground, capable of providing cellular network
coverage over a useful range. Each cellular access point may
communicate with a plurality of cellular client devices such as any
device configured according to the cellular network standards, such
that each cellular client device located within the useful range of
an access point is able to exchange signals with the cellular
network and if needed a WAN. Moreover, the cellular network useful
range may extend over a very wide area when the base station 112
and other access points 114, 116 are configured to exchange radio
signals with adjacent access points to thereby relay radio signals
between the base station 112 and every other cell sight 114, 116.
Accordingly, the cellular network provides a wireless communication
infrastructure for communicating with a plurality of wireless
client devices disposed within the useful range of any cellular
access point and for connecting each client wireless device to a
WAN 100.
[0022] Generally, a cellular network is configured to operate using
radio frequencies ranging from about 0.8-2.2 GHz or using microwave
frequencies ranging from about 2.2-11.0 GHz. In addition, a
cellular network is configured to operate using a cellular network
message exchange or communication protocol standard such as any one
of the Global System for Mobile Communications (GSM), General
Packet Radio Service (GPRS), Universal Mobile Telecommunications
System (UMTS), High-Speed Downlink Packet Access (HSDPA),
High-Speed Uplink Packet Access (HSUPA), Code Division Multiple
Access (CDMA), Evolution-Data Optimized (EVDO), Enhanced Data Rates
for GSM Evolution (EDGE), 3GSM, Digital Enhanced Cordless
Telecommunications (DECT), Digital AMPS (IS-136/TDMA), or
Integrated Digital Enhanced Network (iDEN), etc.
[0023] In practice, different cellular network providers use
different radio frequency bands and or different network exchange
or communication protocol standards. However, it is typical that a
single cell tower may include a plurality of cellular access points
each using a different radio frequency band and or a different
network exchange or communication protocol standard such that the
cellular network 110 may actually comprise a plurality of cellular
networks operating in the same region. Conversely, a typical
cellular client device, e.g. a cell phone or PDA includes a network
interface device configured to communicate with only one type of
cellular network. In addition, each cellular client device is
generally assigned a unique device ID, e.g. a phone number, IP
address, or the like, to uniquely identify the device and to
establish a one to one communication link between the cellular
client device and another device via the access point and cellular
network controller 118.
[0024] The wireless network environment may also include a
Satellite Telecommunication Network, (STN) generally 130. The STN
includes a ground-based base station and network controller, not
shown, and at least one orbiting satellite access point configured
with a transceiver for exchanging electromagnetic signals between
the STN network controller and the, satellite. In addition, the
satellite may transmit broadcast signals to ground based client
devices or may exchange two way communication signals with ground
based STN configured client devices. In one example, an STN may
comprise the global position system, (GPS) used to transmit
wireless signals from satellites to ground-based STN configured
signal receivers for allowing each ground-based STN signal receiver
to calculate its position. Alternately, the STN may comprise one or
more television or radio broadcast satellites configured to
broadcast digitized television and radio, or any other digitized
video and or audio signals, over a wide area to ground based STN
configured client device receivers. In addition, STN-configured
client telephone and video phone devices are able to connect with
other telephone/videophone exchanges through the ground-based STN
network controller. In addition, the ground-based STN network
controller may be in communication with the wire infrastructure 104
and the WAN 100 such that a ground-based STN-configured client
device may gain access to a WAN 100 via a satellite transmission.
As with other networks, the STN controller may control access to
the STN network.
[0025] The network environment may also include one or more
substantially permanent wireless local area networks, (WLAN) 160.
Generally a permanent WLAN 160 comprises a wireless network access
point formed at a base station 164. The permanent WLAN 160 may also
comprise additional wireless access points 166 and 168 disposed to
extend the useable range of the WLAN 160 and configured to
communicate with the base station 164 using wireless and or wire
connections to relay network signals to every access point 164,
166, 168. Each access point 164, 166, 168 includes a wireless
transceiver configured to exchange communication signals with WLAN
configured client devices and with other WLAN access points.
[0026] The base station 164 may include a network controller
configured to host WLAN configured client devices. The network
controller functions as a network router to assign each client
device a network address and to control network traffic between the
host base station 164 and client devices. The base station 164
usually connects with a server 162, which may also form the network
controller, and the server 162 connects with the local wire
infrastructure 104 to provide each client,device with access to the
WAN 100. Generally a permanent WLAN 160 may be installed inside a
structure to provide wireless network access over the entire
structure or a portion thereof In the example network environment,
the WLAN 160 is based on the Wi-Fi or IEEE 802.11 communication
standard which defines how signals are to be formatted and
communicated using radio wave frequencies in the range of 2.4-2.5
GHz and or 5.15-5.8 GHz.
[0027] In addition to the above listed networks, the network
environment may further include a plurality of traditional public
radio and television broadcast networks as well as a plurality of
two-way radio voice and pager networkss all generally represented
by the network access point 190. In particular, the network access
point 190 may comprise broadcast signals able to be received by
properly configured radio or television signal receivers located
within the usable network range, or the network access point 190
may comprise one or more transceivers used for two-way radio
communication by military, municipal, corporate, and private radio
network providers to communicate with any properly configured
signal transceiver located within the usable network range.
Generally the network access point 190 includes broadcast signals
such as free radio, and television broadcast signals pay radio and
television broadcast signals, selected two-way radio communication
bands and various special purpose radio networks.
Mobile Router Interface Devices
[0028] According to the present invention, a mobile router 140
comprises a stand alone wireless network interface device
configured to operate in the above described network environment.
In particular, the mobile router 140 is configured to operate in a
moving vehicle and to access one or more cellular network access
points as the vehicle traverses over a network environment. More
specifically, the mobile router 140 is configured to seek a
cellular access point, to gain access to a cellular network and to
become a client of the cellular network. Once the mobile router is
a client of the cellular network, the mobile router is configured
to exchange network signals with the cellular network. In
particular, the mobile router 140 may be configured to become a
client of one or more cellular networks simultaneously.
[0029] The mobile router 140 is further configured as a wireless
network access point configured to host one or more wireless
network configured devices in a wireless local area network WLAN.
The WLAN may be established inside a vehicle or local to the mobile
router 140. The mobile router 140 comprises a WLAN controller
forming a WLAN base station or access point configured to
communicate with one or more compatibly configured WLAN client
devices. Thus according to the present invention, the mobile router
140 comprises a client device on a cellular network or on a
plurality of cellular networks and a host device communicating with
one or more client devices on a WLAN. Generally, the cellular
network comprises a substantially permanent wireless wide area
network WWAN covering a large geographic region, while the WLAN is
temporary and may be movable with the mobile router 140, e.g. in a
moving vehicle.
[0030] The mobile router 140 is configured to exchange first
network signals with the cellular network or plurality of cellular
networks and to exchange second network signals with one or more
second client devices on the WLAN. Moreover, the mobile router 140
comprises an interface between two or more wireless networks
operating on different network communication standards. More
specifically, the mobile router 140 comprises an interface between
a WWAN and a WLAN.
[0031] As shown in FIG. 1, the mobile router 140 includes a
controller 142, and one or more wireless network interface devices,
144, 146, 148, 150, 152 in communication with the controller 142.
Generally the network interfaces devices shown in FIG. 1 are each
configured to communicate with a different wireless network type
and to deliver network signals originating in each different
network type to the controller 142.
[0032] Each network interface device 144, 146, 148, 150, 152
comprises an antenna configured to receive analog electromagnetic
wave signals in a particular frequency range and a receiver
configured to convert the analog electromagnetic wave signals
received into digital signals formatted as required for delivery to
the controller 142. The receiver may also include a signal
amplifier incorporated in the antenna, incorporated in the mobile
router 140 or installed between the antenna 232 and the router
140.
[0033] Some or all of the network interface devices, 144, 146, 148,
150, and 152 also include a signal transmitter configured to
transmit analog electromagnetic wave signals in a particular
frequency range and with a desired signal power amplitude through
the antenna. Each signal transmitter is configured to receive
digital signals from the controller 142 and to convert the digital
signals into analog electromagnetic wave signals in a particular
frequency range and formatted as required for radio transmission to
another signal receiver. The transmitter may also include a signal
amplifier incorporated in the antenna, incorporated in the mobile
router 140 or installed between, the antenna and the router
140.
[0034] In some instances, an entire network interface device 144,
146, 148, 150, 152 may be disposed external to the wireless router
140 and interfaced with the wireless router by a wire connection
passing through an input output I/O interface device. Alternately,
network interface device may communicate with the router 140
through another wireless interface device included in the mobile
router 140. In particular some vehicles may be equipped with
built-in antennas, GPS receivers, satellite radio and television
receivers etc. and these elements may be used to interface with the
mobile router 140 by wire or wireless connection to deliver network
services to the router 140 for routing to client devices connected
to the router 140.
[0035] Generally, the router controller 142 exchanges control,
communication and power signals with each network interface device
144, 146, 148, 150, 152. The controller 142 may also receive a
network data packet over a first network interface device, e.g. 148
reconfigure the network data packet and transmit the reconfigured
network packet over a second network interface device, e.g.
144.
[0036] In one example according to the present invention, a first
network interface device 144 may comprise a cellular network
interface device configured to communicate with a cellular network
110. In particular, the network interface device 144 exchanges
signals with one or more cellular network access points 112, 114,
116, gains access to become a client of the cellular network 110,
and if possible uses services of the cellular network 110 to gain
access to the WAN 100, to utilize various network services such
viewing web pages, exchanging emails, exchanging voice data,
etc.
[0037] A second network interface device 148 may comprise a WLAN
interface device configured to establish a WLAN network 170. In
particular, the network interface device 148 comprises a WLAN
access point, (AP) used to establish a WLAN network 170 having
network clients 172-178.
[0038] A third network interface device 146 may comprise a personal
area network, PAN, interface device configured to establish a PAN
network 180 and to communicate with PAN network configured devices
182, 184. In particular, the third network device 146 is configured
to host client devices operating on one of the Bluetooth,
Ultra-Wide-Band (UWB) or other PAN network communication
standards.
[0039] A fourth wireless network interface device 150 comprises an
STN interface device configured to communicate with an STN network
or network device 130. In particular, the network interface device
150 exchanges signals with the STN network access point, e.g. the
satellite 130, to gain access to and become a client of the STN
network 130, and if possible to gain access to services of the STN
130, e.g. to gain access to the WAN 100, for telephone and video
conferencing, to access audio and video content, to determine GPS
coordinates, etc.
[0040] A fifth wireless network interface device 152 may comprise
one or more other wireless receivers or transceivers configured to
communicate with two-way radio or pager networks or configured to
receive radio and television broadcast channels from the access
point 190 in FIG. 1. For example the network interface device 152
may comprise a tunable receiver for manually or automatically
scanning or otherwise adjusting to receive an analog
electromagnetic signal of a desired frequency, e.g. a conventional
AM radio signal in the frequency range of 525 kHz to 1715 kHz or
conventional FM radio and television signals in the frequency range
of 30 MHz to 400 MHz, or another broadcast signal. Alternately, the
network interface device 152 may comprise a tunable transceiver for
exchanging two-way radio communication signals over a desired radio
band e.g. a military, marine, municipal, citizen band, corporate,
and amateur or other two-way radio network at selected
frequencies.
[0041] In addition the mobile router 140 may include still further
network interface devices configured for any other specialized
wireless network communication such as Radio Frequency
Identification, (RFID), infrared telecommunication bands, visible
telecommunication bands such as laser emitters and receivers an any
other wireless communication device. In addition, the mobile router
140 may also include one or more wire network interface devices
such as an Ethernet interface device for interfacing with a wired
network such as a local area network LAN when one is available.
Mobile Router Client Device
[0042] Further according to the present invention, the mobile
router 140 comprises a host network device for hosting one or more
client devices. In particular, the WLAN interface device 148
includes a transceiver configured to communicate with WLAN
configured client devices 172, 174 and to exchange WLAN configured
network signals therewith. In addition, the controller 142 is
configured as a WLAN network controller and router for accepting
client devices onto the WLAN network designated 170, and
controlling communication traffic to each client device therein,
172, 174. In addition the controller 142 is configured to receive a
communication signal from a WLAN configured client device, e.g. a
data packet and to reconfigure the data packet for transmission to
a cellular network 110 over the cellular network interface device
144. Conversely, the controller 142 is configured to receive a
reply communication signal, e.g. a return data packet, from the
cellular network 110 and to reconfigure the return data packet for
transmission to a originating WLAN configured client device. As
shown in FIG. 1 the WLAN 170 includes a WLAN configured lap top
computer 172, and WLAN configured speaker and telephone 174,
however, the WLAN clients may include any computer or computer
peripheral device or video displays, PDA's, printers, scanners,
faxes, memory devices, etc. Generally the WLAN may operate
according to one or more of the Wi-Fi, IEEE 802.11, WiMax, IEEE
802.16, wireless Ethernet IEEE 802.3, or any other WLAN
communications standards.
[0043] In addition, the WLAN configured client device 172 may
comprise a network access point for a PAN network 176 which
includes PAN configured client devices 178 such as audio speakers
or headsets, PDA's, key board, mouse, printer, scanner etc.
[0044] In addition or alternately, the PAN network interface device
146 includes a transceiver configured to communicate with PAN
configured client devices and to form a PAN network 180 to exchange
signals with PAN configured client devices 182, 184 as well as PAN
configured devices 176 and 178. In addition, the controller 142 is
configured as a PAN network controller and router for accepting
client devices onto the PAN network 180 and controlling
communication traffic to each client device, 182, and 184. In
addition the controller 142 is configured to receive a
communication signal from a PAN configured client device, e.g. a
data packet and to reconfigure the data packet for transmission
over the cellular network 110 or over any other network locally
reachable by the mobile router 140. Conversely, the controller 142
is configured to receive a reply data packet from the cellular
network 110 or any other network that is locally reachable by the
mobile router 140 and to reconfigure the replay data packet for
transmission to a PAN configured client device, e.g. 182, 184.
Generally the PAN network 180 may operate according to one or more
of the Bluetooth, IEEE 802.15.1, ZigBee, IEEE 802.15.4, Ultra Wide
Band, UMB, IEEE.802.15.3a or any other PAN communications
standards.
The Network Controller
[0045] Turning now to FIG. 2 a mobile router 140 according to the
present invention comprises a controller 142 configured as a
printed circuit board or mother board having various integrated
circuit elements formed thereon and attached thereto. The mobile
router 140 also includes a plurality of network interface devices,
202, 204, 206, 208, 210, 212, 214, 216, 218 and 220 interfaced with
the controller 142 and in communication with the CPU 222. Generally
the controller 142 and each of the network interface devices
202-220 are housed within a conventional electronic module
enclosure 203 configured to protect the enclosed elements from
contaminates, mechanical damage, including shock, moisture,
electromagnetic emissions, electrical shock, and other hazards, as
well as to serve as a common ground plane, all as is well known in
the art._Generally, a network interface device 202-220 may be
configured in a number of different embodiments depending on the
availability and complexity of the interface device. However the
network interface devices may comprise any one of the following
configurations including a combination of more than one
configuration. A separate printed circuit board, such as a daughter
board attached to the controller 142. Printed and additional
circuit elements formed integral with the controller mother board.
Circuit elements contained within a central microprocessor unit,
(CPU) 222. A Portable Computer, (PC), card installed within a card
slot provided through the enclosure 203 and interfaced with the
controller 142 by a card slot interface. An external device
communicating with the controller 142 over a serial or network
interface.
[0046] The controller 142 includes a conventional digital
microprocessor or CPU 222, e.g. offered by INTEL Corp, AMD Corp.
MIPS Corp. etc. Alternately the CPU 222 may be a conventional
Network Storage Processor or the like, specifically configured for
network data processing. The controller 142 includes one or more
digital memory modules 224 in communication with the microprocessor
222 for storing digital data and program instructions therein. The
memory modules 224 may include one or more of various memory types
such as random access memory, (RAM), read only memory ROM, FLASH
ROM, various removable or permanent disk memories etc., and the
memory modules 224 may be mounted on the controller 142, installed
as PC cards or otherwise contained within or associated with the
enclosure 203, including external devices communicating with the
controller 142.
[0047] The controller 142 further includes a power module 226 for
controlling the distribution of power throughout the mobile router
140. The power module 226 may be connected to an external power
source e.g. a conventional AC wall outlet or a conventional 6, 12,
40 or other volt vehicle power outlet, or any other external power
source that is suitably configure to deliver power to the power
module 226, or the power module 226 may include internal power
source elements, e.g. a battery, fuel cell battery charging circuit
etc. Generally the power module interfaces with the microprocessor
222 and with each element of the mobile router 140 through the
controller PC board to deliver and control power as needed, and if
desired to include power saving functionality such as selecting a
different power source, reducing power consumption, activating
power in response to various inputs etc., all in accordance with
predefined power controlling software controlling parameters.
[0048] The mobile router 142 further includes a conventional wire
connecting input output I/O interface 228. The I/O interface 228
includes a plurality of wire connectors supported by the enclosure
203 for connecting and communicating with external devices. In
particular, the I/O interface 228 includes one or more antenna
interfaces 230. Each antenna interface 230 connects with an
external antenna 232 or 246 specifically tuned as an
electromagnetic or magnetic wave receiving and transmitting device
for a desired wireless communication channel or frequency range and
configured to produce an analog electrical signal in response to
electromagnetic or magnetic waves being received thereby or to emit
electromagnetic or magnetic waves in response to an analog
electrical signal. In addition, the external antennas 232 and 246
or antenna interfaces 230 may include a signal amplifier for
amplifying the analog electrical signal produced by or delivered to
the antenna. In addition, each wire connected between the external
antenna 232 and a wireless network interface element 202-218 is
preferably configured to shield and properly ground the antenna
analog signals from external interference and disturbance.
[0049] The I/O interface 228 may also include a wire network
interface 234 including one or more wired network connectors for
connecting the mobile router 140 directly to a wired network such
as a local area network, LAN or wide area network WAN or to any
other wire network configured device including a computer, server,
data storage device, PDA, printer, scanner, video display device,
audio playback system, camera, telephone, router, wireless network
access point, external antenna, modem, etc. In one example, the
wired network interface device 234 is an Ethernet network interface
and the mobile router 140 includes an Ethernet network interface
device 220. The Ethernet interface device 220 may comprise a PC
card in a card slot; a circuit formed on the controller PC board
142 or may be incorporated within the CPU 222.
[0050] Additionally, the mobile router 140 may also have universal
serial bus (USB), Firewire (IEEE 1394), IDE, Serial-ATA interface
devices which provide for interfacing to local data storage devices
(disks) or other peripherals. Serial RS232/422/485 and General
Purpose Interface Bus, (GPIB) (IEE488) interface devices can
interface with other peripherals and the data to and from these
networks can be routed to and from any other connecting network.
Furthermore, local peripherals for control and setting of the
mobile router or for user input/output may exist. These may include
speaker outputs, a video screen, a microphone, or a user-control
(buttons, etc.) on the router itself. All of these peripherals can
be routed to any of the other networks as well. (For instance,
audio or video data from any network can go to the local peripheral
in addition to being routed to attached network devices.)
[0051] The I/O interface 228 includes one or more external power
input connectors 236 for connecting to external power sources. The
I/O interface 228 may include one or more wire ports 238 configured
for serial or parallel communications between the CPU 222 and an
external device, e.g. using an USB or RS232 serial communication
technique. The communication ports 238 may be used to interface
with a computer, server, data storage device, PDA, printer,
scanner, video display device, audio playback system, camera,
telephone, router, wireless network access point, external antenna,
modem etc. The I/O interface 228 may also include one or more
analog or digital-wire ports 242 configured for connecting with an
audio, video, telephone, or other devices as may be required to
exchange analog or digital signals therewith.
[0052] Generally each wireless network interface devices 202-218
includes an integral antenna 240 or an external antenna 232. The
antenna is configured to receive and or transmit or emit
electromagnetic waves of a particular radio or microwave frequency.
Each wireless network interface device 202-218 at least includes a
receiver associated with the antenna for converting antenna signals
into analog electrical signals and for converting the analog
electrical signals into digital signals readable by the CPU 222. In
addition, each wireless network interface device 202-218 may
include a transmitter associated with the antenna for converting
digital signals received from the CPU 222 into analog electrical
signals delivered to the antenna to generate electromagnetic or
magnetic wave signals and to transmit or emit the analog
electromagnetic or magnetic wave signals into the surrounding area.
In addition some wireless network interface devices 202-218 may be
configured as tunable transceivers for tuning to a desired
frequency for receiving various radio, television or microwave
channels such as a radio or television stations or to select a
two-way radio band. In other examples a tunable transceiver may be
used to change cellular networks or to change WLAN networks.
[0053] In one example of a mobile router 140 according to the
present invention, one or more network interface devices 202, 204,
206 are configured as cellular network interface devices for
exchanging electromagnetic wave signals with cellular network
access points, e.g. 112, 114, 116 in FIG. 1, and for becoming a
client device on a cellular network. In addition, one or more
network interface devices 214, 216, 218 are configured as wireless
local area network WLAN or as personal area network PAN access
points for exchanging electromagnetic signals with one or more
client devices configured to communicate with a WLAN or PAN access
point or for becoming a client device on a WLAN or PAN network. In
addition, one or more wireless network interface devices 208, 210
and 212 are configured to communicate with a satellite, (STN, GPS),
radio, (AM/FM, two-way), television, infrared, or any other
wireless network available.
[0054] In a preferred embodiment the mobile router 140 comprises a
first network interface device 202 comprising a 1x Evolution-Data
Optimized, EVDO/1xRTT or just EVDO configured cellular PC card
installed in a card slot connected to the network controller 142.
In addition the EVDO configured interface device 202 is connected
to an external 1.9 GHz PCS antenna 232 through a low loss microwave
cable and bulkhead grommet. The EVDO cellular interface is a Code
Division Multiple Access, (CDMA) wireless broadband data interface
standard used by a large number of cellular network service
provides and access to a cellular network over the EVDO configured
interface device 202 is generally available wherever cellular
access points are available.
[0055] In addition the preferred mobile router 140 comprises a
second network interface device 218 comprising a wireless fidelity,
Wi-Fi configured device for communicating with Wi-Fi configured
client devices. The Wi-Fi or IEEE 802.11 communication standard and
network architecture is used by many wireless local area network
WLAN configured devices and its use is expanding to other devices
such that most wireless network configured devices will be able to
communicate with the Wi-Fi interface device 218.
[0056] Generally, the preferred embodiment described above operates
as follows. Upon power up, the CPU 222 communicates with the first
wireless network interface device 202 to initiate a search for
available EVDO configured cellular network access points and
selects an optimal cellular access point to communicate with. The
CPU 222 may then initiate an action to make the mobile router a
client on the host EVDO configured cellular network 110 and to
access services provided by the cellular network 110. In addition,
the CPU 222 communicates with the second wireless interface device
218 to establish a WLAN 170 over a usable range and to initiate a
search for available Wi-Fi configured client devices 172, 174
located within the usable range. Upon finding Wi-Fi devices, 172,
174, the CPU 222 assigns a Wi-Fi address to each device and
communicates to each client device that a network access point is
available.
[0057] Thereafter, each Wi-Fi client device 172, 174 may
communicate with the Wi-Fi interface device 218 using Wi-Fi network
signals, e.g. to initiate a connection with the WAN 100. The Wi-Fi
network signals are received by the wireless network interface
device 218, converted to digital signals readable by the CPU 222
and reconfigured by the CPU 222 and routed to the EVDO cellular
network interface device 202 to be converted to analog radio
signals and sent to the cellular network 110, and eventually the
WAN 100. Upon receiving a return signal from the WAN 100 and
cellular network 110 in an EVDO format, the first wireless network
interface device 202 converts the analog EVDO signal to a digital
signal readable by the CPU 222 and the CPU 222 converts the return
signal to a Wi-Fi signal and sends the return Wi-Fi signal to the
designated wireless client device 172 or 174.
[0058] Thus according to one aspect of the present invention, the
mobile router 140 acts as a wireless network signal converting
device for converting a Wi-Fi formatted wireless signal to an EVDO
formatted wireless signal and for converting an EVDO formatted
wireless signal to a Wi-Fi formatted wireless signal.
[0059] In further aspects of operating the preferred mobile router
140, the CPU 222 is programmed to periodically update information
about the wireless network environment by repeatedly checking the
availability of a more desirable cellular access point and by
repeatedly checking the status of client devices in the WLAN area
170. This is done to make sure the mobile router 140 stays
continuously connected to the EVDO cellular network even as the
mobile router moves with respect to the wireless environment. In
addition, the wireless router 140 is programmed to repeatedly send
update messages to the cellular network to ensure that host device
does not terminate the client device connection due to inactivity.
In addition, the wireless router 140 is programmed to perform
cellular network access point hand offs without losing a connection
with the host cellular network. In particular this is accomplished
by continuously communicating with two more cellular access points
to hand off communications to the best available access point or if
warranted to divide communication traffic between two or more
cellular access points to increase bandwidth or improve reliability
as may be required.
[0060] Generally the preferred EVDO mobile router 140 including the
external antenna 232 is capable of maintaining a continuous
connection with a cellular network over most of the network
environment. In particular, the external cellular antenna 232,
especially when used with a signal amplifier has a range of
approximately 30 miles, which is significantly better than the
range of an average cell phone or PDA which is typically 0.5-8.0
miles. In addition, the external antenna interface 230 is easily
connected with a built-in vehicle, water craft, or aircraft when
the mobile router 140 is being used therein.
[0061] In addition, the mobile router 140 may also include an
external Wi-Fi antenna 246 optimized for 2.4 GHz signals and
optionally including a signal amplifier to increase the usable
range of the Wi-Fi network 170 and to gain access to another Wi-Fi
network e.g. WLAN 160. In one particularly useful application of
the mobile router 140 configured with an external Wi-Fi antenna
246, the router 140 may be used to access and become a client on a
nearby Wi-Fi configured WLAN 160 and to gain access to a WAN 100
through the WLAN 160. In this case, the usable range of the network
interface device 218 configured with a Wi-Fi optimized external
antenna 246 will usually exceed the range of the client devices 172
and 174 which do not generally include a separate external Wi-Fi
antenna. Thus the mobile router 140 may become a client device of
the WLAN 160 and exchange Wi-Fi signals directly between the client
devices disposed within the WLAN 170 and the WLAN 160. The above
described use of the mobile router 140 is particularly useful when
the only available cellular network is a pay per use service and
the WLAN 160 provides non-pay network access. To take advantage of
this situation, the controller 142 is programmed to review all
available wireless network access points and to select the best
available notwithstanding the network type.
[0062] In further embodiments of the mobile router 140, additional
cellular network interface devices 204 and 206 may be added to
increase the type of cellular networks that can be accessed.
Specifically, each cellular network interface device 202, 204, 206
may be configured to communicate with a different cellular network
type to increase the likelihood that continuous cellular network
access can be maintained. For example the device 202 is configured
as a High Speed Downlink Packet Access (HSDPA) standard cellular
interface device for communicating with one or more HSDPA
configured networks. The device 204 is configured as an Enhanced
Data rates for GSM Evolution, or EDGE interface device for
communicating with one or more EDGE configured cellular networks.
The device 206 is configured as another cellular interface device
as may be required to communicate with another cellular network
type including any one of, or a combination of, the Global System
for Mobile Communications (GSM), General Packet Radio Service
(GPRS), Code Division Multiple Access (CDMA), 3GSM, Digital
Enhanced Cordless Telecommunications (DECT), Digital AMPS
(IS-136/TDMA), and Integrated Digital Enhanced Network (iDEN)
cellular network configurations.
[0063] In further embodiments of the mobile router 140, additional
cellular network interface devices 204 and 206 may be added to
increase the number of cellular network connections that can be
established, e.g. to increase the communication bandwidth capacity
between the mobile router 140 and the cellular network 110. In this
example, each of the cellular network interface devices 202, 204,
206 may comprise an HSDPA configured device and each of the HSDPA
configured devices can be configured to act as a separate client
device on the host cellular network to increase bandwidth.
Moreover, each HSDAP device may have a different cellular network
identity and each device may have a different set of cellular
network service options,
[0064] In further embodiments of the mobile router 140 variously
configured wireless network interface devices 214, 216, 218 may be
used to establish various wireless local area networks, e.g. 170,
180 and others to communicate with devices of various wireless
network configurations. In addition, two or more wireless network
interfaces 214, 216, 218 may be configured as a single type network
device to increase communication bandwidth and or to increase the
number of client device that can be supported. Specifically the
wireless interface devices 214, 216, 218 may be configured
according to any one of the Wi-Fi, IEEE 802.11, Bluetooth, IEEE
802.15, WiMax, IEEE 802.16 Home RF, Ultra Wide Band, UWB, Zigbee,
IEEE 802.15.4, or other wireless networks standards or
protocols.
[0065] In addition, the controller 142 may be configured to operate
in various network environments such as a Mobile ad-hoc Network
(MANET), a peer to peer, P2P networks, a mesh network, an infrared
sensor network, or other network type and exchange signals from one
network type to another as described above.
[0066] Referring to FIG. 3 a preferred embodiment of a mobile
router 300 according to one aspect of the present invention is
shown schematically. The mobile router 300 includes a printed
circuit (PC) board 314 formed with wire buses and associated
surface mounted connectors and circuit elements disposed thereon
and arranged to distribute and exchange analog, digital and power
signals as required to function as a network router. The PC board
314 may be housed in a conventional electronic enclose having side
walls 304, 306, 308 and 310 as well as opposing top and bottom
walls not shown. The mobile router 300 includes an I/O interface
module 312 comprising a plurality of connectors, generally
supported on the PC board 314 and extending through the side wall
308, for receiving wire connector elements therein. The I/O
interface module 312 includes two Ethernet wire network connectors
332 and 334, a power connector 336, (e.g. for receiving AC and or
DC power input), and other wire and or optical connectors 338 as
may be required. The other wire connectors may include wire or
optical ports for exchanging signals with another device including
serial, parallel or other network data ports for exchanging audio,
video text or graphic content with another device.
[0067] The router PC board 314 includes a programmable central
microprocessor unit, (CPU) 222, a memory module 224, in
communication with the CPU 222, and a power module 226 configured
to receive input power from the power connector 336 and to deliver
power to the CPU 222, and to other internal, or externally
connected, components as may be required. The power module 226 may
also comprise a battery or other self contained power generating or
power storage elements.
[0068] In a preferred embodiment, the router 300 includes one
cellular wireless network interface device 316 configured to
exchange radio network signals between a cell site, such as a
cellular telephone network cell tower, (328, 340, 342), and the CPU
222. The preferred router 300 also includes two wire network
interface devices 320 and 321, each configured to exchange network
signals between a wire network or wire network configured device,
e.g. a LAN 333 or a portable computer (PC) 352, and the CPU
222.
[0069] In another embodiment, the router 300 may only include two
network interface devices, the cellular wireless network interface
device 316 and any one of the WLAN wireless network interface
device 316 or wire network interface device 320 or 321.
Alternately, the router 300 may include four network interface
devices 316, 318, 320 and 321 while only being connected to two or
three networks, or while only exchanging network traffic between
two or three networks unless there is a need to reroute network
traffic to the third or fourth network. In a particularly preferred
embodiment, the WLAN wireless network interface device 316
comprises a WiFi configured wireless access point (AP) and each of
the wire network interface devices 320, 321 comprises wire Ethernet
network internet device configured as an Ethernet network node.
[0070] In a first application, the wireless router 300 serves as an
interface between a WiFi network 360 and a cellular network. In
this application, the mobile router 300 is particularly useful for
providing an interface between one or more isolated WiFi client
devices 332 and a cellular network to provide the WiFi client
devices 332 with Internet or WAN access over the cellular network.
Applicants have found that the wireless router 300 is particular
useful in a moving vehicle for exchanging network traffic between
WiFi configured client devices inside the vehicle and destination
public IP addresses available over a cellular network. In another
example, the wireless router 300 operating as a WiFi AP in
otherwise non-WiFi covered areas is usable for exchanging network
traffic between WiFi configured client devices located within about
100 meters of the router 300 and destination public IP addresses
available over a cellular network. This application is particularly
useful for establishing a temporary WLAN such as at a trade show,
or at a temporary office or work space.
[0071] In a second application, the wireless router 300 serves as
an interface between one or both of the two wire network interface
devices 320 and 321 and a cellular network. In this application,
the mobile router 300 is particularly useful for providing an
interface between one or more isolated Ethernet configured client
devices and a cellular network to provide Ethernet configured
client devices with Internet or WAN access over the cellular
network. Applicants have found that the wireless router 300 is
particular useful in a moving vehicle for exchanging network
traffic between on or two a wire Ethernet configured client device,
e.g. PC 352, plugged into the Ethernet connectors 332 and or 334
and destination public IP addresses available over a cellular
network.
[0072] In another example, the mobile router 300 may be installed
as a node on a LAN 333 and used to exchange network traffic between
any node or client device on the LAN 333 and destination public IP
addresses available over a cellular network. This application is
particularly useful for establishing a temporary LAN such as at a
trade show, or at a temporary office or work space.
[0073] In a third application the wireless router 300 serves as an
interface between the WiFi network 360, the LAN 333, a single wire
network configured device PC 352 and a cellular network. In the
example of FIG. 3, a wire Ethernet LAN 333 may be connected to the
wireless router 300 at connector 332 and a wire Ethernet configured
PC 352 may be connected to the wireless router 300 at connector 334
such that the wireless router 300 serves as an interface between
each of the WiFi network 360, the LAN 333, the PC 352 and a
cellular network to exchange network traffic between any locally
reachable client device and any destination public IP address
available over the cellular network.
[0074] In one example embodiment the LAN 333 may comprise a LAN
server 350 and the server 350 may or may not have internet or WAN
access over an ISP 362. The LAN 333 may include one or more LAN
hubs 354 and other LAN client devices 356 associated with the LAN
hub 354. The LAN 333 may also include individual client devices 358
such as a PC, a printer, a scanner, a camera, a media storage
device, or the like. Additionally any wire Ethernet configured
device such as a PC, a printer, a scanner, a camera, a media
storage device, or the like, may be connected to the router at the
wire Ethernet connector 334. Similarly, the WiFi network 360 may
comprise various WiFi configured client devices such as, computers,
computer peripherals, PDA's, telephones, audio arid or video
devices, etc. Generally each wire network device connected to the
mobile router at the wire Ethernet connectors 332 and 334 or
communicating with the WiFi AP 330 is locally reachable by the
router 300.
[0075] In the case where neither the LAN 333 nor WiFi has Internet
or WAN access, e.g. when the LAN 333 does not include the ISP 362,
all of the network traffic received by the router 300 from a
locally reachable device and having a destination IP address that
is not locally reachable is directed over the cellular network
interface device 316 to a cellular network. Conversely, the mobile
router 300 routes any network traffic received from the cellular
network to the appropriate locally reachable device.
[0076] In the case where the LAN 333 includes the ISP 362, all of
the network traffic received by the router 300 from a locally
reachable device and having a destination IP address that is not
locally reachable may be directed over the ISP 362 as a default
gateway. Except that if the ISP 362 is not available, the router
300 may be configured to redirect all non-locally reachable network
traffic over the cellular network as an alternate gateway. In other
examples, the router 300 may be configured to direct non-locally
reachable network traffic over both the cellular network and the
ISP 362 in accordance with preset rules such as directing all
circuit switched data traffic over the cellular network and all
packet switched data traffic over the ISO 362. Otherwise, the
network traffic may be divided or load balanced according various
criteria such as evenly dividing outgoing packets over each gateway
or by using dividing rules or weights based on the bandwidth or
other suitability of a gateway for a particular application. In
addition, each gateway may serve as a backup for all data traffic
in the event that one gateway becomes unavailable. In one
particularly useful application, Applicants have found that the
mobile router 300 functions well as a back up to a disabled or busy
ISP for time critical small data exchanges, such as for confirming
credit card information at point of sale locations or at a self
service kiosk or health care provider location.
WWAN
[0077] Generally the client devices 332 plus the wireless router
300 together form a Basic Service Set (BSS) of radio stations. The
BSS includes one AP, which in the present example is the router
wireless network interface device 318, and one or more client
devices 322. Each client includes a wireless network interface
device, like the device 318, and each wireless network interface
device includes a radio transceiver and an antenna configured to
transmit and receive radio signals in a designated range of radio
frequencies. Generally, each client device 332 communicates
directly with the AP 318. In the present example, the BSS forms a
WLAN 360. The WLAN 360 is operated by the CPU 222, which operates
the WLAN 360 to receive data packets from each of the client
devices 332 and to route the data packets to a destination IP
addresses embedded within a header of each data packet. In
addition, the CPU 222 sends data packets to the client devices 332
if the client device IP address matches the data packet dekination
address.
[0078] As is customary in computer networks, each client device as
well as the AP comprises a network node having a unique node ID
such as the Media Access Control, (MAC) address of its network
interface device. In addition, each network node may have a unique
"host name" selected by a user or by a manufacturer. In addition,
the entire network, (WLAN 360), has a unique network ID, which may
be the MAC address or hostname of the AP, in this case, the network
interface device 318. Generally, client devices 332 may enter and
or leave the WLAN 360 by moving into and out of communication range
of the AP or by powering on or off. However, the CPU 222 uses
program steps stored in the memory device 224 to track the identity
of each active client device 322 in the WLAN 360 and to add and
delete devices from active status.
[0079] In a preferred embodiment, each node of the WLAN 360 is
configured as a WiFi device using radio signals in the radio
frequency spectrum approximately centered around 2.4 GHz and using
data packets configured and exchanged according to the WiFi
communication protocol described in the IEEE 802.11 communication
standard. Accordingly, the wireless router network interface device
318 includes a 2.4 GHz antenna 330, which may be housed inside an
enclosure surrounding the PC board 314 or which may extend
externally through an enclosure wall, e.g. wall 306. Generally, the
CPU 222 performs program steps to operate the network interface
device 318 as a WiFi AP that periodically broadcasts its WiFi
network ID to potential client devices and functions to exchange
WiFi network signals with client devices 332 within about 30-100
meters of the mobile router 300.
LAN
[0080] Generally, the mobile router 300 includes two wire network
interface devices 320 and 321 for interfacing two different wire
network configured devices. In the example of FIG. 3, a first wire
network, LAN 333, is interfaced with the connector 332 and the
first wire network interface device 320. A second wire network
comprises a PC 352 which is connected with the connector 334 and
the second wire network interface device 321. Alternately, the two
wire network interface devices 320 and 321 can interface with any
two wire network configured individual devices or any two wire
LAN's.
[0081] As described above, the LAN 333 may comprise any number of
client devices or nodes connected to a common wire bus. Each node
of the LAN 333 includes a wire network interface device that has a
unique node ID such as its Media Access Control, (MAC) address, its
host name, or both. In addition, the entire LAN 333 has a network
ID which may be the MAC address of the first wire network interface
device 320. Generally, LAN client devices may be added and deleted
to the first wire network by connecting with or disconnect from the
LAN wire bus or powering on or off.
[0082] The second wire network includes two nodes, the individual
device, PC 325, and the network interface device 321. Each node has
a unique node ID, such as a MAC address and or host name, and the
second network has a second network ID, which may be the MAC
address of second wire network interface device 321. As in the
first wire network, client devices may be added to and deleted from
the second wire network by connecting with or disconnect from the
wire network interface device 321, or by powering on or off.
[0083] In a preferred embodiment, each of the first and second wire
network interface devices 320 and 321 is configured as a wire
Ethernet device and each of the wire network client devices of the
first and second wire networks is configured as a wire Ethernet
device. Generally, each client device communicates directly with
its associated wire network interface device 320 or 321. The CPU
222 operates two different wire networks to receive data packets
from each wire network and to route the data packets to a
destination IP addresses embedded within a header of each data
packet. In addition, the CPU 222 sends data packets to each wire
network client device if the client device IP address matches the
data packet destination address.
Cellular Network
[0084] Generally a cellular network is any radio network made up of
a plurality of radio cells. Each radio cell is served by a main
transceiver, (usually fixed), known as a cell site, e.g. 328, 340
and 342. Each user of a cellular network is provided with a user
transceiver, (usually mobile), and user transceivers are
distributed over each of the radio cells. In the example of FIG. 3,
the cellular wireless network interface device 316 is a cellular
network user transceiver. Cellular network traffic including data
packets are exchanged between the user transceiver 316 and one or
more cell sites, 328, 340 and 342 using radio signals. In addition,
cell sites may exchange data packets with one or more base station
servers 364. Generally, the base station server 364 receives all
incoming cellular network traffic and routes it to its destination
address. If the destination address of a data packet is not locally
reachable by the base station server 364, the base station forwards
the data packet to a switching exchange 366 which interfaces with
public and private telephone exchange networks, other cellular
networks, and or computer networks, e.g. on the Internet until the
destination address is reached. Accordingly, the phrase "cellular
network" as used herein refers to a radio network of cell sites and
user devices each having a radio transceiver configured to exchange
radio signals, a base station server 364 and a switching exchange
366 for interfacing with other networks.
[0085] One example of a cellular network is a commercial cellular
telephone network such as those provided in the United States by
ATT Wireless, Sprint, Verizon Wireless, Cingular and T-Mobile and
others. Cellular telephone network cell sites are serviced by main
transceivers called cell towers and the most common user device
transceivers are cellular telephones and PDA's. Generally cellular
telephone radio networks communicate using radio frequencies
approximately center around 1.9 GHz, however other radio frequency
bands are usable. In addition, some commercial cellular telephone
networks are configured to provide efficient wireless computer
network services specifically tailored to provide computer network
services over a WWAN.
[0086] Another example of cellular network is a restricted access
radio or microwave network deployed over a campus or over an entire
community or region. Restricted access radio and microwave networks
include public safety networks used by law enforcement, fire,
medical, military and other agencies for providing public safety
and other services. Other restricted access cellular network
examples include cellular networks established in seaports,
airports, industrial complexes, and the like, or for communicating
with a fleet of vehicles over a region. A restricted access
cellular network operates the same as the cellular networks
described above except that restricted access cellular networks may
use different radio frequency bands such as centered around 4.9 GHz
or in selected bands up to about 5.85 GHz used for high bandwidth
public safety data exchanges over a restricted cellular
network.
[0087] In addition, other cellular networks or WWAN's may provide
open or less restricted network access to user devices configured
with a microwave frequency based Worldwide Interoperability for
Microwave Access, (WiMAx) or IEEE 802.16 communication standard
network interface device. In particular, such cellular networks
include Municipal Area Networks (MAN's) having a plurality of cell
sites deployed over a municipality or campus and communicating with
hundreds or thousands of user devices using selected microwave
frequency bands in the range of 2-11 GHz. In particular, the WiMax
bands include 2.1 and 5.8 GHz.
[0088] Referring now to FIG. 3, the example cellular network
depicted therein is a commercial cellular telephone network that
includes cellular towers 328, 340 and 342 each servicing a cell
site extending over a geographic region approximately corresponding
in size with the practical radio signal range of the cellular
tower, e.g. from 0.5 miles in an obstructed area up to about 20
miles in an unobstructed area. Each cellular tower includes a radio
transceiver and antenna specifically configured to simultaneously
exchanging radio signals with hundreds or thousands of cellular
network configured mobile or stationary user devices, (mostly
cellular telephones), located within the cell. In addition, each
cellular tower 328, 340, 342, may exchange radio or other signals
with the base station server 364 and with other destination IP
addresses beyond the switching exchange 366.
[0089] In addition, while the cellular network operates to exchange
radio signals between one user device and one cellular tower 328,
the signal exchange may be handed off to another cellular tower,
e.g. 340 and 342 as conditions of the network change. In
particular, as the location of a user device changes within a radio
cell or as a user device moves to a different radio cell, a
different cellular tower (e.g. 340) may provide higher signal
strength or other more appropriate characteristic for handling a
communication session. Generally handoffs are carefully controlled
to avoid a drop or interruption in an active communications session
such that some cellular telephone networks may allow a user to
communicate with two cell towers simultaneously.
[0090] The mobile router 300 comprises a cellular network
configured user device able to communicate with a cellular tower
328, 340, 342 over the cellular network interface device 316. As
with other networks, each cellular network user device and each
cellular network tower comprises a network node having a unique
cellular network node ID. The node ID may comprise a device
specific number, like a cellular MAC address, a telephone number, a
host name, or a public or private IP address. In the present
example, the cellular network interface device 318 has a MAC
address used by the router 300 and a public IP address which is
assigned to it by the cellular network.
[0091] Preferably the cellular network interface device 316 is
configured to communicate with a cellular network using a widely
available cellular communication standard such as the
Evolution-Data Optimized, (EVDO) cellular communication standard,
used by Sprint and Verizon Wireless in the United States, the High
Speed Downlink Packet Access (HSDPA) standard, used by Cingular, or
the Enhanced Data Rates for Global System Mobile Evolution (EDGE)
communication standard, used by Cingular and T-Mobile in the United
States. However, other cellular data standards are usable and the
mobile router 300 may be configured with two or more differently
configured cellular network interface devices 316 or with a
cellular network interface card slot that allows a user to
interchange different cellular network interface devices 316
configured to communicate with differently configure cellular
networks. Preferably the cellular network interface device 316 is
directly coupled to an externally mounted 1.9 GHz PCS cellular
antenna 322 by a low loss microwave cable 324. Preferably the
antenna 322 is pivotally supported with respect to an enclosure
wall 310 by a bulkhead grommet 326 to pivot the antenna to improve
signal reception. However, other cellular antenna configurations
are usable including using a single antenna coupled to two separate
cellular network interface devices 316.
Mobile Router
[0092] To operate as a router, the CPU 222 utilizes program steps
stored in the memory module 224 to control the operation of router
300. In particular, upon power up, the CPU 222 determines which
network interface devices 316, 318, 320 and 321 are installed and
assigns a separate bus to each network interface device. In
addition, the CPU determines the MAC address of each network
interface device 316, 318, 320 and 321 and stores the MAC addresses
in a routing table. The CPU 222 then assigns a non-routable network
or subnet IP address and a subnet mask to each locally reachable
network. These include the WiFi interface device 318 and WiFi
network 360, the first Ethernet interface device 320, and the LAN
333, and the second Ethernet interface device 321, and the PC 352.
Each subnet IP address comprises a network address that uniquely
identifies the network. Each subnet mask IP address includes a
network portion, (the subnet IP address), plus a node portion that
uniquely identifies each node. The node portion may be one octet of
the IP address which provides 255 non-routable private subnet IP
addresses for nodes on the network or two octets can be assigned to
node address to provide 65K node addresses.
[0093] In example of FIG. 3, the subnet. IP address of the WiFi
network is assigned the network address 192.168.100 and the first
node or client device in the WiFi network is assigned the IP
address 192.168.100.0. The subnet IP address of the first Ethernet
network is assigned the network address 192.168.101 and the first
node or client device in the first Ethernet network is assigned the
IP address 192.169.101.0. Likewise, subnet IP address of the second
Ethernet network is assigned the network address 192.168.102 and
the first node or client device in the second Ethernet network is
assigned the IP address 192.169.102.0. This addressing
scheme'uniquely associates each node or client device with the
locally reachable network that the node is associated with.
[0094] Once the addresses are reserved, the CPU 222 then commands
the WiFi network interface device 318 to communicate with any WiFi
clients in the communication range of the WiFi AP 318 and to
determine the MAC address of each WiFi client and assign each WiFi
client with a unique subnet mask IP address. The CPU 222 then
commands each wire Ethernet network interface device 320 and 321 to
communicate with any wire Ethernet clients locally connected to the
wireless router 300, to determine the MAC address of each Ethernet
client device and to assign each Ethernet client with an
appropriate unique subnet mask IP address.
[0095] Once all of the locally reachable devices are identified,
the CPU 222 generates a routing table listing the MAC ID, host
name, network ID and subnet mask IP address of every locally
reachable device or client. The routing table is stored in the
memory device 224. In addition, the routing table may also store
other information related to a node such a port assignment as may
be required. In addition, the CPU 222 periodically poles each
network for configuration changes and updates the routing table
accordingly.
[0096] After populating the routing table with the local devices,
the CPU 222 then initiates steps that cause the cellular network
interface device 316 to communicate with a cellular tower 328 and
to establish a network connection with a cellular network. In
response to the communication from the cellular network interface
device 316, the cellular network assigns the cellular network
interface device 316 with a temporary public IP address which is
the temporary public IP address of the mobile router 300 and of
every device locally reachable over the router 300. The CPU 222
then adds the public IP address to the routing table for use as the
source IP address for all network traffic routed over the cellular
network interface device 316.
[0097] In addition, the CPU 222 may also store instantaneous
conditions of the cellular network such as an identity of the
cellular tower, e.g. tower 328, the tower location, if known, the
proximity of other towers, if known, etc. Moreover, the CPU 222 may
calculate instantaneous conditions of the cellular network such as
the signal strength of each cellular tower, the up and down load
bandwidth capacity of the tower, tower response time and or other
parameters of the cellular network as can be determined. All
instantaneous and set conditions of the cellular network may then
be stored in a database or look up table stored in the memory
device 224 and Used by the CPU 222 to select routing paths.
Moreover, the CPU 222 periodically poles the cellular network for
configuration changes and updates of the instantaneous and set
conditions of the cellular network and updates any databases or
tables stored in the memory device 224.
[0098] Generally, the router 300 receives network traffic from
locally reachable devices and uses Network Address Translation,
(NAT), and or Network Address Port Translation, (NAPT) to route
traffic from locally reachable devices to pubic IP address
destinations over the, cellular network. In particular the router
300 has a single public IP address assigned to the network
interface device 318 by the cellular network. As network traffic
passes from the locally reachable devices to the router and then to
public IP address destinations reachable over the cellular network,
the CPU 222 translates each data packet on the fly to remove its
locally reachable source address and local port assignment and
replace these with the public IP address of the network interface
device 318 and an assigned return port. In addition, the CPU 222
and memory device 224 are programmed to track basic information
about outgoing packets (particularly the local IP address, local
port assignment, destination IP address and assigned return port)
and to store the outgoing packet information in the routing table
or other database. Accordingly, when a reply packet from the
destination IP address returns to the router 300 over the assigned
return port, the CPU 222 accesses the outgoing packet information
stored in the routing table or database and re-translates the reply
packet to insert the local source IP address and local port
assignment and routes the reply packet accordingly.
[0099] In particular, each data packet is formatted with a header
at the beginning of the packet, a payload, containing the
information to be carried, and a trailer marking the end of the
packet. The header generally includes instructions to the router.
The instructions include the packet source IP address the packet
destination IP address and may include a local port assignment.
Upon receiving a packet, the CPU 222 reads the source and
destination IP addresses and determines if the destination IP
address is a locally reachable address by searching the routing
table. If the destination IP address is locally reachable, the
packet is routed to the destination IP address without changing the
header information. If the destination IP address is not locally
reachable, the packet header information is modified by the CPU
222. In particular, the packet local source IP address is removed
and replaced by the public IP address assigned to cellular network
interface device 316. Accordingly, the public IP address assigned
to cellular network interface device 316 is used as the source IP
address for every packet sent over the cellular network. The CPU
222 also assigns the packet a unique return port, adds the return
port ID to the packet header and logs the packet destination
address, return port assignment, local IP address and local port
assignment if one was included, into the routing table or into a
packet tracking database or table as required. Thereafter, any
reply packet received from the destination IP address over the
assigned return port is immediately routed to the local IP address
over the local port assigned to the session. Accordingly, the
mobile router 300 acts as a network interface between one or more
local networks and or individual devices and a cellular network to
route data packets from locally reachable devices to any public IP
address reachable by the cellular network.
Mobile Router Stack
[0100] Referring now to FIGS. 3 and 4, a plurality of mobile
routers, each configured substantially like the mobile router 300,
shown in FIG. 3 and described above, are stacked together in a
stack 400. In particular, the stack 400 includes a master router
402 and one or more substantially identical slave-routers 404, 406
and 408. The routers may be held in a stack configuration e.g. by a
stack holder such as a rack or bracketing element, not shown. Each
router in the stack includes a power connector 336 separately
plugged into a power source; however other power delivery options
are usable. Each router in the stack includes a cellular network
interface device 316 and an externally disposed cellular antenna
322. Each router in the stack may include a WiFi network interface
device 318, however, in the stack 400, only the master router 402
establishes the WALN 360. Accordingly, none of the slave routers
404-408 need to include a WiFi network interface device 318. The
stack 400 may comprise two routers, e.g. 402 and 404 with one
master router 402 and one slave router 404. Alternately, the stack
400 may comprise one master router 402 combined with any number of
slave routers. Additionally, each router in the stack may include
two or more cellular network interface devices 316 directly
interfaced with the local CPU and operating substantially like the
cellular network interface 316 as described above and below.
[0101] Each router 402-408 includes two,wire Ethernet connectors
332 and 334 with each connector 332 being associated with a first
wire Ethernet network interface device 320 and with each Connector
334 being associated with a second wire Ethernet network interface
devices 321. In the stack configuration, a wire Ethernet configured
jumper wire 410 connects the master router second Ethernet network
interface device 321 with the first Ethernet network interface
device 320 of the first slave router 404. Additionally, wire
Ethernet configured jumper wires 412 and 414 connect the second
Ethernet network interface device 321 of the slave router 404 with
first Ethernet network interface device 320 of the slave router 406
and the second Ethernet network interface device 321 of the slave
router 404 with the first Ethernet network interface device 320 of
the slave router 408. In this manner, the stack 400 comprises an
Ethernet network with each router 402, 404, 406 and 408 comprising
a network node.
[0102] Generally each router 300 includes program steps stored in
the memory module 224 for operating as either a master router or a
slave router. To set up a router stack, a user may interface with
CPU 222 using an external computer in communication with the CPU
222. The user may use the external computer to access the routers
user menu stored on the memory module 224. The router user menu can
be used to configure each router as a master router or a slave
router. Moreover, the user menu can be used to assign each router
in a stack a device number and according to the present invention
setting a router to device number 1 configures the router as a
master router and setting the device number to higher numbers
configures a router as a slave router. Generally, if a customer
orders a router stack, the configuration of each router can be
preset prior to shipment and the stack 400 can be shipped
assembled. Alternately, if a user desires to set up a stack 400
using single routers, the CPU 222 of each router can determine if
the router is associated with a stack 400, determine its position
in the stack 400 and configure itself as a master router or a slave
router as required.
[0103] As stated above, upon power up, the CPU determines which
network interface devices 316, 318, 320 and 321 are installed and
assigns a separate bus to each network interface device. In
addition, the CPU determines the MAC address of each network
interface device 316, 318, 320 and 321 and stores the locally
reachable MAC addresses in a routing table. In addition, the CPU
222 determines if the second Ethernet network interface device 321
is interfaced with another router 300 and if so determines its
position in the stack and sets its configuration as a master router
402 or a slave router 404-408 as required.
[0104] With the router 402 set as a master router and any other
routers in the stack configured as slave routers, the master router
402 operates as described above to establish the WiFi network 360
and an Ethernet network with whatever devices are interfaced with
the master router first Ethernet network interface device 320, e.g.
the LAN 333, shown in FIG. 4. The master router 402 assigns a
non-routable network or subnet IP address and a subnet mask to each
locally reachable network including the WiFi interface device 318
and WiFi network 360 and the first Ethernet interface device 320,
and the LAN 333. Since the second Ethernet interface device 321 is
interfaced with the slave router 402, the slave router 404 is
treated as if it was another cellular network interface device 316.
Similarly any other slave routers 406 and 408 in the stack are
treated as if there were cellular network interface devices
316.
[0105] Thus each stack 400 includes at least one cellular network
interface device 316 per router such that a stack of two routers
effectively doubles the cellular network bandwidth that the router
stack can gain access to. In the stack 400, the master router 402
has up to four times the cellular network bandwidth available to it
as compared to a single router 300. Accordingly a stack 400 can
route as much as four times the network traffic over a cellular
network as a single router 300 because the stack 400 utilizes four
cellular network interface devices 316.
[0106] In the stack 400, the master router 402 determines that
there are four cellular network interface device 316 installed in
the stack and initiates steps that cause each of the four network
interface device 316 to communicate with a cellular tower 328 and
to establish a separate network connection with a cellular network.
In response to the communication from each of the four cellular
network interface devices 316, the cellular network assigns each
cellular network interface device 316 with a temporary public IP
address. The master router 402 then receives the temporary public
IP address of each cellular network interface device 316 in the
stack and stores each public IP address in its routing table as a
potential source address usable for outgoing network traffic.
[0107] Accordingly the master router 402 constructs a routing table
with the node ID of every device that is locally reachable by the
master router 402 and with the public IP address of each cellular
network interface device 316 in the stack 400. Thus the stack 400
has four public IP addresses usable to exchange network traffic
with the cellular network. Moreover, the cellular network treats
the stack 400 as if it were four different independent client
devices. Thus as the stack moves through a cell site or moves from
one sight to another, the cellular network controls handoffs and
communication session changes with the four cellular network
interface device 316 independently. This has the advantage that
while a communication session with one cellular network interface
device 316 may be dropped, other cellular network interface device
316 will remain connected and available to reroute outgoing network
traffic.
[0108] In operation, the master router 402 receives network traffic
from locally reachable devices and uses Network Address
Translation, (NAT) and or Network Address Port Translation, (NAPT)
to route traffic from locally reachable devices to pubic IP address
destinations over all four connections with the cellular network.
In particular, the master router 300 has four public IP addresses
available to assign as a source IP address to an outgoing network
packet. Moreover, since any reply packets are delivered back to the
source IP address assigned to an outgoing packet, reply packets are
also received over all four connections with the cellular network.
This allows the master router to use any suitable scheme to divide
or load balance the outgoing network traffic over the four channels
and or to shift the outgoing network traffic to the best available
channels as required.
[0109] As shown in FIG. 4, any locally reachable client devices are
connected to the master router 402. Network traffic from one
locally reachable device to another locally reachable device flows
through the master router CPU 222. The master router CPU 222 checks
destination address of each data packet against its routing table
and if the destination address is locally reachable, the CPU 222
routes the data packet to the appropriate locally reachable
destination address. If the data packet destination address is not
locally reachable, the master router CPU 222 uses a routing
algorithm and or data stored in the routing table to select which
of the four available cellular network connections to route the
data packet over. Once the outgoing packet is assigned to a
cellular network connection, the master router CPU 222 translates
the packet by replacing the data packet source IP address and local
port assignment with the public IP address assigned to the selected
cellular network connection anti a return port assignment. The
packet is then routed the cellular network interface device 316
associated with the assigned cellular network connection.
Accordingly, the packet may be routed to the cellular network
interface device 316 installed in the master router 402 or to the
cellular network interface device 316 installed in any of the slave
router 404-408 over the Ethernet connections made with each slave
router. In addition the master router CPU 222 is programmed to
track basic information about each outgoing packet, particularly
the local source IP address and local port assignment removed from
the packet, the non-local destination IP address and return port
assignment. In particular, information about each outgoing packet
is stored in the master router memory device 224. Outgoing packet
information may be added to the routing table or may be stored in a
separate packet tracking database. Accordingly, for each data
packet send over the cellular network, the master router CPU 222
updates a table or database with the packet local source IP
address, local port assignment, destination IP address, return port
assignment and assigned public source IP address.
[0110] Each reply packet returned to the stack 400 is received by a
cellular network interface device 316. If the reply packet is
received by a slave router, the slave router CPU routes the packet
over the wire Ethernet connections to the master router CPU 222.
The master router CPU then reads the packet to determine its source
IP address and return port assignment. The master router CPU 222
then compares the reply packet information with the outgoing packet
information stored in the routing table or packet tracking database
to find matching outgoing packet. The master router CPU 222 then
retranslates the reply packet to replace the public IP destination
address and return port assignment with the appropriate locally
reachable IP address and local port assignment stored in the
outgoing packet information stored in the routing table or packet
tracking database. The packet is then routed to the appropriate
locally reachable device.
[0111] It will also be recognized by those skilled in the art that,
while the invention has been described above in terms of preferred
embodiments, it is not limited thereto. Various features and
aspects of the above described invention may be used individually
or jointly. Further, although the invention has been described in
the context of its implementation in a particular environment, and
for particular applications, e.g. a mobile network router, those
skilled in the art will recognize that its usefulness is not
limited thereto and that the present invention can be beneficially
utilized in any number of environments and implementations
including but not limited to any network environment. Accordingly,
the claims set forth below should be construed in view of the full
breadth and spirit of the invention as disclosed herein.
* * * * *