U.S. patent application number 16/183466 was filed with the patent office on 2019-03-07 for remote access to local network.
The applicant listed for this patent is QUALCOMM Incorporated. Invention is credited to Lakshminath Reddy Dondeti, Ranjith Jayaram, Anand Palanigounder, Peerapol Tinnakornsrisuphap, Jun Wang.
Application Number | 20190075078 16/183466 |
Document ID | / |
Family ID | 41666730 |
Filed Date | 2019-03-07 |
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United States Patent
Application |
20190075078 |
Kind Code |
A1 |
Tinnakornsrisuphap; Peerapol ;
et al. |
March 7, 2019 |
REMOTE ACCESS TO LOCAL NETWORK
Abstract
Multiple protocol tunnels (e.g., IPsec tunnels) are deployed to
enable an access terminal that is connected to a network to access
a local network associated with a femto access point. A first
protocol tunnel is established between a security gateway and the
femto access point. A second protocol tunnel is then established in
either of two ways. In some implementations the second protocol
tunnel is established between the access terminal and the security
gateway. In other implementations the second protocol tunnel is
established between the access terminal and the femto access point,
whereby a portion of the tunnel is routed through the first
tunnel.
Inventors: |
Tinnakornsrisuphap; Peerapol;
(San Diego, CA) ; Palanigounder; Anand; (San
Diego, CA) ; Jayaram; Ranjith; (Short Hills, NJ)
; Dondeti; Lakshminath Reddy; (Hyderabad, IN) ;
Wang; Jun; (Poway, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
QUALCOMM Incorporated |
San Diego |
CA |
US |
|
|
Family ID: |
41666730 |
Appl. No.: |
16/183466 |
Filed: |
November 7, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15140211 |
Apr 27, 2016 |
10142294 |
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16183466 |
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12619162 |
Nov 16, 2009 |
9345065 |
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15140211 |
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61115520 |
Nov 17, 2008 |
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61145424 |
Jan 16, 2009 |
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61150624 |
Feb 6, 2009 |
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61164292 |
Mar 27, 2009 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 12/2838 20130101;
H04L 63/029 20130101; H04W 92/02 20130101; H04L 63/164 20130101;
H04L 63/08 20130101; H04L 67/125 20130101; H04L 67/08 20130101;
H04W 88/16 20130101; H04L 12/4633 20130101; H04L 63/0272 20130101;
H04L 12/2803 20130101; H04L 61/1511 20130101; G06F 3/1454 20130101;
H04L 2012/285 20130101; H04L 12/66 20130101; H04W 84/105 20130101;
H04W 84/045 20130101; H04W 88/08 20130101; H04W 76/12 20180201;
H04L 67/025 20130101; G06F 1/3209 20130101 |
International
Class: |
H04L 29/06 20060101
H04L029/06; H04L 29/12 20060101 H04L029/12; H04W 92/02 20090101
H04W092/02; H04W 76/12 20180101 H04W076/12; H04L 12/46 20060101
H04L012/46; H04L 12/66 20060101 H04L012/66 |
Claims
1. A method of communication, comprising: identifying a femto
access point to be accessed by an access terminal; and sending a
message from the access terminal to a security gateway to enable
the access terminal to access the femto access point, wherein the
message comprises an identifier of the femto access point.
2. The method of claim 1, wherein the femto identifier is embedded
in another identifier that the access terminal uses for
authentication with the security gateway.
3. An apparatus for communication, comprising: a mobility
controller configured to identify a femto access point to be
accessed by an access terminal; and a communication controller
configured to send a message from the access terminal to a security
gateway to enable the access terminal to access the femto access
point, wherein the message comprises an identifier of the femto
access point.
4. The apparatus of claim 3, wherein the femto identifier is
embedded in another identifier that the access terminal uses for
authentication with the security gateway.
5. An apparatus for communication, comprising: means for
identifying a femto access point to be accessed by an access
terminal; and means for sending a message from the access terminal
to a security gateway to enable the access terminal to access the
femto access point, wherein the message comprises an identifier of
the femto access point.
6. The apparatus of claim 5, wherein the femto identifier is
embedded in another identifier that the access terminal uses for
authentication with the security gateway.
7. A non-transitory computer-readable medium storing computer
executable code for causing the computer to: identify a femto
access point to be accessed by an access terminal; and send a
message from the access terminal to a security gateway to enable
the access terminal to access the femto access point, wherein the
message comprises an identifier of the femto access point.
8. The computer-readable medium of claim 7, wherein the femto
identifier is embedded in another identifier that the access
terminal uses for authentication with the security gateway.
Description
CLAIM OF PRIORITY
[0001] This application is a divisional of U.S. patent application
Ser. No. 15/140,211, filed Apr. 27, 2016, entitled "REMOTE ACCESS
TO LOCAL NETWORK," which is a divisional of U.S. patent application
Ser. No. 12/619,162, filed Nov. 16, 2009, entitled "REMOTE ACCESS
TO LOCAL NETWORK," which claims the benefit of and priority to
commonly owned U.S. Provisional Patent Application No. 61/115,520,
filed Nov. 17, 2008; U.S. Provisional Patent Application No.
61/145,424, filed Jan. 16, 2009; U.S. Provisional Patent
Application No. 61/150,624, filed Feb. 6, 2009; and U.S.
Provisional Patent Application No. 61/164,292, filed Mar. 27, 2009,
the disclosure of each of which is hereby incorporated by reference
herein.
BACKGROUND
Field
[0002] This application relates generally to wireless communication
and more specifically, but not exclusively, to improving
communication performance.
Introduction
[0003] Wireless communication systems are widely deployed to
provide various types of communication (e.g., voice, data,
multimedia services, etc.) to multiple users. As the demand for
high-rate and multimedia data services rapidly grows, there lies a
challenge to implement efficient and robust communication systems
with enhanced performance.
[0004] To supplement conventional mobile phone network access
points, small-coverage access points may be deployed (e.g.,
installed in a user's home) to provide more robust indoor wireless
coverage to mobile access terminals. Such small-coverage access
points may be referred to as femto access points, access point base
stations, Home eNodeBs ("HeNBs"), Home NodeBs, or home femtos.
Typically, such small-coverage access points are connected to the
Internet and the mobile operator's network via a digital subscriber
line (DSL) router or a cable modem.
[0005] In some cases, one or more local services may be deployed at
the same location as a small-coverage access point. For example, a
user may have a home network that supports a local computer, a
local printer, a server, and other components. In such cases, it
may be desirable to provide access to these local services via the
small-coverage access point. For example, a user may wish to use
his or her cell phone to access a local printer when the user is at
home.
[0006] In general, a node on the public Internet may not be able to
initiate communication with a device on a home network because this
device is protected by a firewall and the network address
translator (NAT) within the home router. Accordingly, a need exists
for efficient and effective methods for remotely accessing a local
network.
SUMMARY
[0007] A summary of sample aspects of the disclosure follows. In
the discussion herein, any reference to the term aspects may refer
to one or more aspects of the disclosure.
[0008] The disclosure relates in some aspects to using multiple
protocol tunnels (e.g., IPsec tunnels) to enable an access terminal
that is connected to a network (e.g., an operator's network, the
Internet, etc.) to access a local network associated with a femto
access point. A first protocol tunnel is established between a
security gateway and the femto access point. A second protocol
tunnel is then established in either of two ways. In some
implementations the second protocol tunnel is established between
the access terminal and the security gateway. In other
implementations the second protocol tunnel is established between
the access terminal and the femto access point, whereby a portion
of the tunnel is routed through the first tunnel.
[0009] Through the use of these schemes, an access terminal may
reach a local Internet Protocol (IP) network or server that is in
the same domain as a femto access point even when the access
terminal is not connected over-the-air with the femto access point.
Thus, a remotely located access terminal may be provided with the
same local IP capability as when the access terminal is connected
to the femto access point over-the-air.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] These and other sample aspects of the disclosure will be
described in the detailed description and the appended claims that
follow, and in the accompanying drawings, wherein:
[0011] FIG. 1 is a simplified block diagram of several sample
aspects of a communication system where an access terminal remotely
accesses a local network via protocol tunnels terminating at a
security gateway;
[0012] FIG. 2 is a flowchart of several sample aspects of
operations that may be performed to provide remote access to a
local network via protocol tunnels terminating at a security
gateway;
[0013] FIG. 3 is a flowchart of several sample aspects of
operations that may be performed to discover a security
gateway;
[0014] FIG. 4 is a simplified block diagram of several sample
aspects of a communication system where an access terminal remotely
accesses a local network via layered protocol tunnels;
[0015] FIG. 5 is a flowchart of several sample aspects of
operations that may be performed to provide remote access to a
local network via layered protocol tunnels;
[0016] FIG. 6 is a simplified block diagram of several sample
aspects of components that may be employed in communication
nodes;
[0017] FIG. 7 is a simplified diagram of a wireless communication
system;
[0018] FIG. 8 is a simplified diagram of a wireless communication
system including femto access points;
[0019] FIG. 9 is a simplified diagram illustrating coverage areas
for wireless communication;
[0020] FIG. 10 is a simplified block diagram of several sample
aspects of communication components; and
[0021] FIGS. 11-16 are simplified block diagrams of several sample
aspects of apparatuses configured to facilitate remote access to a
local network as taught herein.
[0022] In accordance with common practice the various features
illustrated in the drawings may not be drawn to scale. Accordingly,
the dimensions of the various features may be arbitrarily expanded
or reduced for clarity. In addition, some of the drawings may be
simplified for clarity. Thus, the drawings may not depict all of
the components of a given apparatus (e.g., device) or method.
Finally, like reference numerals may be used to denote like
features throughout the specification and figures.
DETAILED DESCRIPTION
[0023] Various aspects of the disclosure are described below. It
should be apparent that the teachings herein may be embodied in a
wide variety of forms and that any specific structure, function, or
both being disclosed herein is merely representative. Based on the
teachings herein one skilled in the art should appreciate that an
aspect disclosed herein may be implemented independently of any
other aspects and that two or more of these aspects may be combined
in various ways. For example, an apparatus may be implemented or a
method may be practiced using any number of the aspects set forth
herein. In addition, such an apparatus may be implemented or such a
method may be practiced using other structure, functionality, or
structure and functionality in addition to or other than one or
more of the aspects set forth herein. Furthermore, an aspect may
comprise at least one element of a claim.
[0024] FIG. 1 illustrates several nodes of a sample communication
system 100 (e.g., a portion of a communication network). For
illustration purposes, various aspects of the disclosure will be
described in the context of one or more access terminals, access
points, and network nodes that communicate with one another. It
should be appreciated, however, that the teachings herein may be
applicable to other types of apparatuses or other similar
apparatuses that are referenced using other terminology. For
example, in various implementations access points may be referred
to or implemented as base stations or eNodeBs, access terminals may
be referred to or implemented as user equipment or mobiles, and so
on.
[0025] Access points in the system 100 provide one or more services
(e.g., network connectivity) for one or more wireless terminals
(e.g., access terminal 102) that may be installed within or that
may roam throughout a coverage area of the system 100. For example,
at various points in time the access terminal 102 may connect to an
access point 106 (e.g., a femto access point associated with a
local network) or other access points (e.g., macro access points,
not shown in FIG. 1). Each of the access points may communicate
with one or more network nodes to facilitate wide area network
connectivity.
[0026] These network nodes may take various forms such as, for
example, one or more radio and/or core network entities. Thus, in
various implementations a network node may provide functionality
such as at least one of: network management (e.g., via an
operation, administration, management, and provisioning entity),
call control, session management, mobility management, gateway
functions, interworking functions, or some other suitable network
functionality. In the example of FIG. 1, sample network nodes are
represented by, IP network 110, a security gateway 112 (e.g., a
femto security gateway), and an authentication server 114 (e.g., an
authentication, authorization, and accounting (AAA) entity; a
visiting location register (VLR), or a home location register
(HLR)) and router 120.
[0027] The nodes in the system 100 may employ various means to
communicate with one another. Depending on its location, the access
terminal 102 may communicate with an IP network 110 (e.g., to an
access point of the IP network 110, not shown) or the access point
106. In the example of FIG. 1, the access terminal 102 is connected
to an IP network 110 as represented by a communication link 118
(e.g., via a wireless or wired connection). The access point 106
may connect to a router 120 as represented by a communication link
122, the router 120 may connect to the Internet 124 as represented
by a communication link 126, the security gateway 112 may connect
to the Internet 124 as represented by a communication link 128, and
the security gateway 112 may connect to the IP network 110 as
represented by a communication link 130.
[0028] Through the use of these communication links, the access
terminal 102 may communicate with various nodes in the system 100.
When the access terminal 102 is connected to the IP network, the
access terminal 102 may, for example, access services via an
operator core network (e.g., the core network of a cellular
network) or some other network. Thus, the access terminal 102 may
communicate with other access terminals and other networks.
[0029] When the access terminal 102 is connected to the access
point 106, the access terminal may access nodes on a local network
on which the access point 106 resides along with one or more local
nodes (represented by local node 134). The local node 134 may
represent a device that resides on the same IP subnetwork as the
access point 106 (e.g., a local area network served by the router
120). In this case, accessing the local network may involve
accessing a local printer, a local server, a local computer,
another access terminal, an appliance (e.g., a security camera, an
air conditioner, etc.), or some other entity on the IP subnetwork.
When connected to the access point 106, the access terminal 102 may
access the local network without going through the operator core
network 110. In this way, the access terminal 102 may efficiently
access certain services when the access terminal is, for example,
at a home network or some other local network.
[0030] When the access terminal 102 is connected to some other
access point (e.g., the access terminal 102 is operating remotely
in another network), the access terminal 102 may not be able to
readily access the local network due to a firewall at the router
120. In the discussion that follows two architectures are described
for enabling an access terminal to remotely access a local
network.
[0031] FIGS. 1 and 2 describe an architecture that employs two
protocol tunnels, both of which terminate at the security gateway
112. The first protocol tunnel is established between the security
gateway 112 and the access point 106. The second protocol tunnel is
established between the security gateway 112 and the access
terminal 102.
[0032] FIGS. 4 and 5 describe an architecture that employs two
protocol tunnels, both of which terminate at the access point 106.
The first protocol tunnel is established between the security
gateway 112 and the access point 106. The second protocol tunnel is
established between the access point 106 and the access terminal
102, whereby a portion of the second protocol tunnel is established
within the first protocol tunnel.
[0033] In some aspects, these architectures may make use of an IP
port opened by the protocol tunnel established between the security
gateway 112 and the access point 106 to enable remote access. In
the architecture of FIG. 1, the security gateway 112 inspects the
packets received via the tunnel from the access terminal 102 and
forwards these packets to the tunnel to the access point 106. In
the architecture of FIG. 4, the security gateway simply routes
tunneled inbound packets from the access terminal 102 to tunnel to
the access point 106, and vice versa.
[0034] Advantageously, these architectures may have good synergy
with conventional femto access point implementations. For example,
a femto access point that supports local IP access may already
support assigning local IP addresses for access terminals and
performing proxy address resolution protocol (ARP) functions. In
addition, a femto access point may already have a persistent IPsec
tunnel with its femto security gateway that traverses through any
network address translation (NAT) between the femto access point
and the femto security gateway. Also, there may be no need to
provision additional authentication information (e.g.,
authentication information) for remote access terminal access
(e.g., for authentication, authorization, and secure IPsec tunnel).
The authentication information for remote access may be derived
using one of the existing authentication information that the
access terminal shares with the local (e.g., home) network or the
operator's network.
[0035] The following implementation details may be used in
conjunction with the described architectures. An operator may offer
remote IP access as an add-on service on a subscription basis.
Capabilities such as dynamic host configuration protocol (DHCP)/ARP
are available at the femto access point to support remote IP
access. Femto access points that can be reached by a given access
terminal may be configured as part of the access terminal
(subscription) profile at a home authentication server. Femto
access points may be identified by a femto identifier or by realm
(e.g., useful for groups of femto access points in enterprise
deployments). A user may invoke the service on demand at the access
terminal (e.g., by clicking "My Home").
[0036] Referring again to FIG. 1, sample aspects of this
architecture will now be described in more detail. The security
gateway 112 acts as a virtual private network (VPN) gateway for a
protocol tunnel established with the access terminal 102. In FIG.
1, traffic flow between the access terminal 102 and the security
gateway 112 (e.g., via links 118, and 130) is represented by dotted
line 136 routed via a protocol tunnel (e.g., an IPsec tunnel) as
represented by a pair of lines 138. Here, the inner source and
destination addresses of a packet sent by the access terminal will
have local network addresses (e.g., as assigned by the router 120),
while the outer source and destination addresses will be, for
example, the macro IP address of the access terminal 102 and the IP
address of the security gateway 112, respectively.
[0037] The security gateway 112 forwards any packets received from
the access terminal 102 to the access point 106 via a protocol
tunnel established with the access point 106. In FIG. 1, traffic
flow between the security gateway 112 and the femto access point
106 (e.g., via links 128, 126, and 122) is represented by dotted
line 140 within a protocol tunnel (e.g., an IPsec tunnel) as
represented by a pair of lines 142. In this tunnel, the inner
source and destination addresses of packet sent by the access
terminal will again be the local network addresses discussed in the
previous paragraph, while the outer source and destination
addresses will be, for example, defined by the tunnel 142.
[0038] Access terminal authentication is performed with the
authentication server 114 (e.g., a home AAA) using a suitable
algorithm. For example, some implementations may employ internet
key exchange version 2 (IKEv2) extensible authentication
protocol-authentication and key agreement (EAP-AKA or IKEv2
pre-shared key (PSK) (e.g., reusing the existing IP subscription
authentication information for the access terminal, e.g., as
configured by an operator). The femto access point may provide DHCP
server functionality which the security gateway 112 may request
local IP to assign to the access terminal as part of IKEv2.
[0039] The security gateway 112 forwards selected packets from the
access point 106 to the access terminal 102 (e.g., based on a
forwarding policy or a target address). The security gateway 112 is
reachable via the macro IP address of the access terminal 102.
Through the use of the above scheme, the access terminal 102 may
use any available IP connectivity for remote IP access.
[0040] In some implementations (e.g., when the access terminal 102
is on a remote network that is different than the operator network
for the access point 102), an address conflict may arise when
routing packets from the access point 106 to the access terminal
102. To address this issue, separate child security associations
(CSAs) may be defined for the tunnel 142. For example, a first CSA
may be used to route traffic from the access point 106 that is
destined for the access terminal 102 (e.g., remote IP access
traffic). A second CSA may then be used to route traffic from the
access point 106 that is destined for the operator core network
110. The security gateway 112 may determine where to route a packet
received from the access point 106 based on which CSA the packet
was received on. CSAs may be advantageously employed here since
another unique protocol tunnel need not be defined and the
authentication information of the tunnel 142 may be reused.
[0041] Sample operations of the system 100 will now be described in
more detail in conjunction with the flowchart of FIG. 2. For
convenience, the operations of FIG. 2 (or any other operations
discussed or taught herein) may be described as being performed by
specific components (e.g., components of the system 100). It should
be appreciated, however, that these operations may be performed by
other types of components and may be performed using a different
number of components. It also should be appreciated that one or
more of the operations described herein may not be employed in a
given implementation.
[0042] As represented by block 202, at some point in time (e.g.,
when the access point 106 is deployed) a first protocol tunnel is
established between the security gateway 112 and the access point
106. Here, the security gateway 112 and the access point 106 each
perform corresponding operations to establish the protocol tunnel.
This may involve, for example, exchanging messages to allocate
cryptographic keys for encrypting and decrypting information sent
over the protocol tunnel 142. In addition, as mentioned above, CSAs
may be established for this protocol tunnel.
[0043] As represented by block 204, at some point in time the
access terminal 102 obtains authentication information. For
example, the wireless operator for the access terminal 102 may
assign authentication information when the access terminal is first
provisioned.
[0044] As represented by block 206, at some point in time the
access terminal 102 may identify an access point (e.g., access
point 106) on a local network. For example, the access terminal 102
may be associated with a home femto access point when either of
these devices is provisioned.
[0045] As represented by block 208, at some point in time the
access terminal 102 discovers the security gateway associated with
the access point 106. For example, the access terminal 102 may be
at a location that is outside the wireless coverage of the access
point 106, yet is able to connect to some other network (e.g., a
wireless operator's macro network). In this case, the access
terminal 102 may attempt to locate the security gateway that is
associated with the access point 106 so that the access terminal
102 may gain access to its local network. As discussed in more
detail in conjunction with FIG. 3, this may involve, for example,
the access terminal 102 sending a message to one or more security
gateways to find the security gateway that has established a tunnel
to the access point 106. In conjunction with this message, the
access terminal 102 sends its authentication information to the
security gateway. The security gateway then takes appropriate
action to authenticate the authentication information (e.g., by
communicating with the authentication server 114). For example, the
security gateway may send the subscription information for the
access terminal 102 to the authentication server 114. The
authentication server 114 maintains a list a femto access points
that may be accessed as part of the subscription profile for the
access terminal 102 (i.e., the access terminal subscription profile
determines whether a given user is authorized to use a given femto
access point). Based on an identifier (e.g., network access
identifier (NAI)) received during authentication (e.g., an
identifier obtained as a result of a message sent by the access
terminal 102 to the security gateway 112), the authentication
server 114 returns one or more femto identifiers to the security
gateway, e.g., identifying the femto access points that the access
terminal 102 is allowed to access (assuming the access terminal 102
is successfully authenticated). The received identifier may also
additionally comprise (e.g., imply or have imbedded within) the
identity of the femto access point that the access terminals want
to access (e.g., contained as part of the NAI). If multiple femto
identifiers are returned, the security gateway selects a femto
identifier (e.g., based on the availability of an IPsec tunnel to
the femto access point and any preference indicated by the access
terminal 102). In the event the security gateway has established a
tunnel to the access point 106 (e.g., the access terminal 102 has
queried the security gateway 112) and the authentication
information of the access terminal 102 has been authenticated, the
security gateway sends a response to the access terminal and the
entities commence setting up the protocol tunnel 138.
[0046] As represented by block 210, in conjunction with setting up
the protocol tunnel 138, an address on the local network is
obtained for the access terminal 102. For example, the security
gateway 112 may send a message to the access point 106 requesting a
local address on behalf of the access terminal 102. As one example,
in a CSA dedicated to remote IP access, the security gateway 112
sends a DHCP request or router solicitation via the tunnel 142 to
the access point 106 to request a remote IP address for the access
terminal 102. The access point 106 may then send a request to the
router 120 for the local address. Once the access point 106 obtains
the local address, the access point 106 sends the local address to
the security gateway 112. The security gateway 112 then forwards
the local address to the access terminal 102 (e.g., once the
protocol tunnel 138 is established). For example, the assigned
address may be sent to the access terminal 102 via an IKE_AUTH
message.
[0047] As represented by block 212, the security gateway 112 and
the access terminal 102 each perform corresponding operations to
establish the protocol tunnel 138. This may involve, for example,
exchanging messages to allocate cryptographic keys for encrypting
and decrypting information sent over the protocol tunnel 138.
[0048] As represented by block 214, once the protocol tunnel 138 is
established, packets may be routed between the access terminal 102
and the access point 106 via the protocol tunnels 138 and 142.
Here, the security gateway 112 routes packets it receives via one
tunnel to the other tunnel. This may be accomplished in various
ways. In some cases, a forwarding policy is established at the time
of setting up the protocol tunnels. Thus, when a packet is received
via a given tunnel, that packet is forwarded based on the policy.
Here, the security gateway 112 may identify a packet from a given
tunnel based on, for example, the IPsec protocol header
encapsulating the packet. In some cases, the security gateway 112
inspects the packets to obtain an identifier of the source (e.g.,
the access terminal 102) and/or the destination (e.g., the access
point 106) for the packet. The security gateway 112 may then
determine the appropriate tunnel for forwarding the packet based on
this extracted identifier information.
[0049] The access point 106 routes packets between the tunnel 142
and the local network. For example, when a packet is received at
the access point 106 via the tunnel 142, the access point 106
inspects the packet to identify the destination for the packet on
the local network. The access point 106 and forwards the packet to
the identified destination. FIG. 1 illustrates a sample data path
144 for packet flow between the access point 106 and the local node
134 of the local network (e.g., via the router 120).
[0050] As mentioned above, to remotely access a local network
associated with an access point, an access terminal may need to
discover the security gateway that is being used by the access
point. Here, it may be assumed that the security gateway is
publically reachable (e.g., a node may reach the security gateway
via public IP). FIG. 3 describes two techniques that may be
employed to discover a security gateway. One technique involves
domain name server (DNS) resolution and multiple retries. The other
technique involves security gateway redirection based on, for
example, subscription information.
[0051] As represented by block 302, the access terminal 102 will
have identified an access point on a local network that the access
terminal 102 wishes to access. For example, as discussed above in
conjunction with block 206, the access terminal 102 may acquire a
femto identifier of the femto access point on a home network that
the access terminal 102 is allowed to access.
[0052] As represented by block 304, in implementations that employ
the DNS technique, the access terminal 102 sends a DNS query
including a designated domain name of one or more security gateways
in the system. In response to this query, the access terminal 102
may receive a list of one or more security gateway addresses. Using
this technique, the access terminal 102 may attempt to connect to
each IP address sequentially. Here, only the correct security
gateway will succeed. If the correct security gateway is found, the
access terminal may cache the address information for that security
gateway as discussed below. In practice, the addresses returned
from the DNS server are usually randomized in a round robin fashion
for load balancing. Hence, it is unlikely that a single security
gateway will be "hit" constantly if this technique is used.
[0053] As represented by block 306, the access terminal 102
initiates discovery for the security gateway. In a case where the
DNS technique is used, the access terminal may use an address
obtained from the DNS query at this point. Regardless of the
technique being used, the access terminal 102 may send a message to
a selected security gateway to determine whether that security
gateway has established a tunnel to the access point 106. The
selected security gateway receives this message from the access
terminal 102 as represented by block 308.
[0054] As represented by block 310, the security gateway determines
whether a tunnel has been established to the access point 106. For
example, based on one or more femto identifiers received from the
authentication server 114 (e.g., as described above), the security
gateway determines whether there is already a pre-setup IPsec
tunnel to the corresponding femto access point.
[0055] As represented by block 312, the security gateway sends an
appropriate response to the access terminal 102 based on the
determination of block 310.
[0056] If the tunnel has been set up, the tunnel 138 may be
established. Here, if the tunnel 142 does not have a CSA associated
with remote IP access, the security gateway 112 may request the
access point 106 to create another CSA. The security gateway 112
then connects the new CSA with the tunnel 142 to the access
terminal 102. As represented by block 314, the access terminal 102
may then maintain the address of the security gateway 112 (e.g.,
along with a mapping to the access point 106) so that the access
terminal 102 may avoid searching for that security gateway in the
future.
[0057] If the tunnel had not been set up, the security gateway
sends an appropriate response to the access terminal 102. For
example, in some implementations the security gateway may reject
the request from an access terminal (e.g., via an appropriate error
code using IKEv2).
[0058] Alternatively, in implementations that employ the
redirection technique, the security gateway may redirect the access
terminal 102 to the correct security gateway. Here, the operator
may maintain a database (e.g., redirection database 146) that maps
access point identifiers (e.g., femto identifiers) to security
gateway addresses. This database is then made accessible for the
security gateways in the network. Thus, the security gateway may
determine the address of the correct security gateway associated
with the designated access point and send that address information
to the access terminal 102 in the response.
[0059] When a femto is being authenticated at the security gateway,
the authentication server 114 may store security addresses for
later. Here, different authentication servers (e.g., home AAAs) in
the network may have some means to retrieve security gateway
addresses associated with femto identifiers from other
authentication servers (e.g., femto AAAs) in the network. For
example, these different types of authentication servers may be
implemented in the same entity or share the same database.
[0060] As represented by block 316, as a result of a rejection or a
redirection response, the access terminal 102 commences discovery
of another security gateway. For example, in an implementation that
uses the redirection technique, the access terminal 102 may next
access the security gateway corresponding to the address provided
in the response. In an implementation that uses the DNS technique,
the access terminal 102 may select the next address in the list of
addresses that was obtained at block 304.
[0061] From the above, it should be appreciated that different
discovery techniques may be independently employed or that multiple
discovery techniques may be employed in combination. For example,
the DNS technique and the redirection technique may be employed in
combination since the access terminal does not need to know whether
the security gateway can redirect or not. In addition, if the
security gateway does not redirect the access terminal, the access
terminal can still try the next security gateway IP address on its
own.
[0062] Referring to FIG. 4, sample aspects of the architecture
illustrated by the system 400 will now be described in more detail.
The system 400 includes components that are similar to the
components of FIG. 1. Specifically, the access terminal 402, the
access point 406, the security gateway 412, the communication links
418, 422, 426, 428, and 430, the router 420, and the Internet 424
are similar to similarly named components of FIG. 1. FIG. 4 also
shows an example where the access point 404 may connect to a PSDN
408 as represented by a communication link 416 and the PSDN 408 may
connect to an operator network 410 as represented by a
communication link 418. Other types of network connectively may be
used in other implementations as well (e.g., as discussed in FIG.
1).
[0063] As in the system 100 of FIG. 1, the system 400 enables a
remotely located access terminal 402 to access a local network on
which an access point 406 resides. Again, in a typical scenario,
the access point 406 is a home femto access point of the access
terminal 402 or some other access point that permits access by the
access terminal 402.
[0064] In this architecture, the access point 406 acts as a virtual
private network gateway for a protocol tunnel established with the
access terminal 402. In FIG. 4, traffic flow between the access
terminal 402 and the access point 406 is represented by dotted line
436 routed via a protocol tunnel (e.g., an IPsec tunnel) as
represented by a pair of lines 438. Here, the inner source and
destination addresses of a packet sent by the access terminal 402
will have local network addresses (e.g., as assigned by the router
420 through the access point 406 acting as a proxy ARP for the
access terminal 402), while the outer source and destination
addresses will be, for example, macro IP address of the access
terminal 402 and the access point 406, respectively.
[0065] Traffic flow between the security gateway 412 and the access
point 406 is provided via a protocol tunnel (e.g., an IPsec tunnel)
as represented by a pair of lines 448. Here, it may be seen that
the tunnel 438 is carried (e.g., encapsulated or layered) within
the tunnel 448. Thus, packets arriving at the security gateway 412
from the access point 402 are inserted into the tunnel 448.
Accordingly, the outer headers for the tunnel 438 including the
outer source and destination addresses described in the preceding
paragraph are not removed in this architecture. Rather, another set
of outer source and destination addresses are added to the packet
and will be, for example, defined by the tunnel 448. Thus, when a
packet arrives at the access point 406, two layers of tunnel
headers will be removed from the packet to obtain the packet with
the source and destination addresses associated with the local
network.
[0066] Conversely, when sending a packet from the local network to
the access terminal 402, the access point 406 encapsulates the
packet for transmission via tunnel 438, then encapsulates the
resulting packet for transmission via the tunnel 448. The security
gateway 412 will then remove the header for the tunnel 448 and
route the packet to the access terminal 402. With the above in
mind, additional details relating to the operations of the system
400 will be described with reference to the flowchart of FIG.
5.
[0067] As represented by block 502, at some point in time a first
protocol tunnel is established between the security gateway 412 and
the access point 406. The security gateway 412 and the access point
406 each perform corresponding operations to establish the protocol
tunnel. This may involve, for example, exchanging messages to
allocate cryptographic keys for encrypting and decrypting
information sent over the protocol tunnel 448.
[0068] As represented by block 504, at some point in time the
access terminal 402 and the access point exchange authentication
information (e.g., shared authentication information for IKEv2 SA
authentication). Advantageously, the authentication information for
the tunnel does not need to be pre-provisioned in the access
terminal 402.
[0069] For example, the authentication information may be derived
locally while the access terminal is connected over-the-air through
the access point 406. Here, if the access terminal is able to
access the local network via the access point 406 when connected
over-the-air to the access point 406, the access terminal 402
already has access to any IP hosts on the local domain. This
capability may thus be preserved when the access terminal is at a
remote location.
[0070] Various techniques may be employed here. For example, in a
first alternative, a Diffie-Hellman key exchange may be performed
to generate a pre-shared key (PSK) while the access terminal 402
connects over-the-air locally. In a second alternative, an
authenticated Diffie-Hellman key exchange may be performed to
generate a pre-shared key (PSK) while the access terminal 402
connects over-the-air locally. In this case, a secret (e.g.,
password) used for the authentication may be provided to the user
during subscription of the user's service. During the
Diffie-Hellman exchange, the user may enter this secret on the
access terminal 402. The access point 406, in turn, may obtain the
secret from the network (e.g., from a AAA entity) during PPP
authentication and authorization. A key also could be generated at
the network using AAA exchange (where the access point sends its
Diffie-Hellman values to the network). After the Diffie-Hellman
exchange, the access terminal 402 and the access point share PSK.
In a third alternative, EAP-AKA (over point-to-point protocol
(PPP)) may be used to generate a minimum-shift keying (MSK) and the
MSK may then be used as the PSK. In a fourth alternative, GBA may
be used to generate PSK between the access terminal 402 and the
access point 406. Here, the access point 406 may play the role of
network application function (NAF) and contact bootstrapping
service function (BSF) for bootstrapping. At the end of
bootstrapping, the access terminal 402 and the access point 406
share PSK.
[0071] The authentication information also may be derived when the
access terminal is connected remotely (e.g., through a macro access
point or femto access point). For example, the authentication
information may be derived during IKEv2 security association (SA)
establishment between the access terminal 402 and the access point
406 while the access terminal is in macro coverage (e.g., connected
to macro access point 404). A shared key may be derived using
similar techniques as described in the alternatives above. For the
first and second alternative, PSK may be generated during IKEv2
initialize security association (INIT_SA) Diffie-Hellman exchange.
For the third alternative, EAP-AKA is performed during IKEv2. For
the fourth alternative, generic bootstrapping architecture (GBA)
may be used, with standardized IKEv2 based network application
function interface (Ua) (NAF--user equipment (UE)) protocol.
[0072] The access terminal 402 may acquire the IP address of the
access point 406 in various ways. In some implementations, when the
access point 406 is registered with the network, the access point
406 may be assigned a fully qualified domain name (FQDN) in a
private DNS belonging to the operator. In this case, the access
terminal may use this FQDN to reach the access point 406. In some
implementations, the access terminal 402 may learn the IP address
of the access point 406 when the access terminal 402 connected with
the access point 406 over-the-air.
[0073] Referring again to FIG. 5, as represented by block 506, the
access terminal discovers the access point 406 to be used to access
the desired local network. These operations may be similar to the
discovery operations described above.
[0074] As represented by block 508, in conjunction with
establishing the second protocol tunnel (tunnel 438), an address on
the local network is obtained for the access terminal 402. As
above, the access point 406 may send a request to the router 420
for the local address. In some cases, the access point 406 then
sends the local address to the security gateway 412 which, in turn,
forwards the local address to the access terminal 402.
[0075] As represented by block 510, the access point 406 and the
access terminal 402 each perform corresponding operations to
establish the second protocol tunnel. This may involve, for
example, exchanging messages to allocate cryptographic keys for
encrypting and decrypting information sent over the protocol tunnel
438.
[0076] As represented by block 512, once the protocol tunnel 438 is
established, packets may be routed between the access terminal 402
and the access point 406 via the protocol tunnels 438 and 448. For
a tunneled packet received from the access terminal 402, the
security gateway 412 encapsulated the packets for transmission over
the tunnel 448. For a packet received from the access point 406,
the security gateway 412 removes the encapsulation for the tunnel
448 and sends the tunneled packet to the access point 406. As
above, this may be accomplished using a forwarding policy or some
other suitable technique.
[0077] Also as above, the access point 406 routes packets between
the tunnels 448 and 438 and the local network. For example, when
packets are received at the access point 406 via the tunnels, the
access point 406 inspects the packets to identify the destination
for the packet on the local network. The access point 406 and
forwards the packet to the identified destination. FIG. 4
illustrates a sample data path 444 for packet flow between the
access point 406 and the local node 434 of the local network (e.g.,
via the router 420).
[0078] FIG. 6 illustrates several sample components that may be
incorporated into nodes such as an access terminal 602, an access
point 604, a security gateway 606, and an authentication server 642
(e.g., corresponding to the access terminal 102 or 402, the access
point 106 or 406, the security gateway 112 or 412, and the
authentication server 114, respectively) to perform access
operations as taught herein. The described components also may be
incorporated into other nodes in a communication system. For
example, other nodes in a system may include components similar to
those described for the access terminal 602, the access point 604,
and the security gateway 606 to provide similar functionality. A
given node may contain one or more of the described components. For
example, an access terminal may contain multiple transceiver
components that enable the access terminal to operate on multiple
frequencies and/or communicate via different technologies.
[0079] As shown in FIG. 6, the access terminal 602 and the access
point 604 may include transceivers 608 and 610, respectively, for
communicating with other nodes. The transceiver 608 includes a
transmitter 612 for sending signals (e.g., to an access point) and
a receiver 614 for receiving signals (e.g., from an access point).
Similarly, the transceiver 610 includes a transmitter 616 for
sending signals and a receiver 618 for receiving signals.
[0080] The access point 604 and the network node 606 also include
network interfaces 620 and 622, respectively, for communicating
with one another or other network nodes. For example, the network
interfaces 620 and 622 may be configured to communicate with one or
more network nodes via a wired or wireless backhaul.
[0081] The access terminal 602, the access point 604, and the
security gateway 606 also include other components that may be used
in conjunction with access operations as taught herein. For
example, the access terminal 602, the access point 604, the
security gateway 606, and the authentication server 642 include
communication controllers 624, 626, 628, and 644, respectively, for
managing communication with other nodes (e.g., processing and
inspecting packets, obtaining authentication information, obtaining
identifiers, or sending and receiving packets, messages, requests,
addresses, authentication information, responses, or queries) and
for providing other related functionality as taught herein. In
addition, the access terminal 602, the access point 604, and the
security gateway 606 include tunnel controllers 630, 632, and 634,
respectively, for establishing tunnels and for providing other
related functionality (e.g., accepting or rejecting access terminal
access to a tunnel) as taught herein. The access terminal 602
includes a mobility controller 636 for identifying access points to
be accessed and for providing other related functionality as taught
herein. The access terminal 602 includes a data memory 638 for
maintain security gateway addresses and for providing other related
functionality as taught herein. The access point 604 includes an
address controller 640 for obtaining local addresses and for
providing other related functionality as taught herein. The
authentication server 642 includes a database 646 for storing
subscription information for providing other related functionality
as taught herein.
[0082] For convenience the access terminal 602 and the access point
604 are shown in FIG. 6 as including components that may be used in
the various examples described herein. In practice, one or more of
the illustrated components may be implemented in a different way in
a different example. As an example, the tunnel controllers 630,
632, and 634 may have different functionality and/or operate in a
different manner (e.g., establish tunnels in a different manner) in
the implementation of FIG. 1 as compared to the implementation of
FIG. 4.
[0083] Also, in some implementations the components of FIG. 6 may
be implemented in one or more processors (e.g., that uses and/or
incorporates data memory). For example, the functionality of blocks
624, 630, 636, and 638 may be implemented by a processor or
processors of an access terminal, the functionality of blocks 620,
626, 632, and 640 may be implemented by a processor or processors
in of access point, and the functionality of blocks 622, 628, and
624 may be implemented by a processor or processors in a network
node.
[0084] As discussed above, in some aspects the teachings herein may
be employed in a network that includes macro scale coverage (e.g.,
a large area cellular network such as a third generation (3G)
network, typically referred to as a macro cell network or a wide
area network) and smaller scale coverage (e.g., a residence-based
or building-based network environment). As an access terminal moves
through such a network, the access terminal may be served in
certain locations by access points that provide macro coverage
while the access terminal may be served at other locations by
access points that provide smaller scale coverage. In some aspects,
the smaller coverage access points may be used to provide
incremental capacity growth, in-building coverage, and different
services (e.g., for a more robust user experience).
[0085] In the description herein, a node that provides coverage
over a relatively large area may be referred to as a macro access
point while a node that provides coverage over a relatively small
area (e.g., a residence) may be referred to as a femto access
point. It should be appreciated that the teachings herein may be
applicable to nodes associated with other types of coverage areas.
For example, a pico access point may provide coverage (e.g.,
coverage within a commercial building) over an area that is smaller
than a macro area and larger than a femto area. In various
applications, other terminology may be used to reference a macro
access point, a femto access point, or other access point-type
nodes. For example, a macro access point may be configured or
referred to as an access node, base station, access point, eNodeB,
macro cell, and so on. Also, a femto access point may be configured
or referred to as a Home NodeB, Home eNodeB, access point base
station, femto cell, and so on. In some implementations, a node may
be associated with (e.g., divided into) one or more cells or
sectors. A cell or sector associated with a macro access point, a
femto access point, or a pico access point may be referred to as a
macro cell, a femto cell, or a pico cell, respectively.
[0086] FIG. 7 illustrates a wireless communication system 700,
configured to support a number of users, in which the teachings
herein may be implemented. The system 700 provides communication
for multiple cells 702, such as, for example, macro cells
702A-702G, with each cell being serviced by a corresponding access
point 704 (e.g., access points 704A-704G). As shown in FIG. 7,
access terminals 706 (e.g., access terminals 706A-706L) may be
dispersed at various locations throughout the system over time.
Each access terminal 706 may communicate with one or more access
points 704 on a forward link (FL) and/or a reverse link (RL) at a
given moment, depending upon whether the access terminal 706 is
active and whether it is in soft handoff, for example. The wireless
communication system 700 may provide service over a large
geographic region. For example, macro cells 702A-702G may cover a
few blocks in a neighborhood or several miles in rural
environment.
[0087] FIG. 8 illustrates an exemplary communication system 800
where one or more femto access points are deployed within a network
environment. Specifically, the system 800 includes multiple femto
access points 810 (e.g., femto access points 810A and 810B)
installed in a relatively small scale network environment (e.g., in
one or more user residences 830). Each femto access point 810 may
be coupled to a wide area network 840 (e.g., the Internet) and a
mobile operator core network 850 via a DSL router, a cable modem, a
wireless link, or other connectivity means (not shown). As will be
discussed below, each femto access point 810 may be configured to
serve associated access terminals 820 (e.g., access terminal 820A)
and, optionally, other (e.g., hybrid or alien) access terminals 820
(e.g., access terminal 820B). In other words, access to femto
access points 810 may be restricted whereby a given access terminal
820 may be served by a set of designated (e.g., home) femto access
point(s) 810 but may not be served by any non-designated femto
access points 810 (e.g., a neighbor's femto access point 810).
[0088] FIG. 9 illustrates an example of a coverage map 900 where
several tracking areas 902 (or routing areas or location areas) are
defined, each of which includes several macro coverage areas 904.
Here, areas of coverage associated with tracking areas 902A, 902B,
and 902C are delineated by the wide lines and the macro coverage
areas 904 are represented by the larger hexagons. The tracking
areas 902 also include femto coverage areas 906. In this example,
each of the femto coverage areas 906 (e.g., femto coverage area
906C) is depicted within one or more macro coverage areas 904
(e.g., macro coverage area 904B). It should be appreciated,
however, that some or all of a femto coverage area 906 may not lie
within a macro coverage area 904. In practice, a large number of
femto coverage areas 906 may be defined with a given tracking area
902 or macro coverage area 904. Also, one or more pico coverage
areas (not shown) may be defined within a given tracking area 902
or macro coverage area 904.
[0089] Referring again to FIG. 8, the owner of a femto access point
810 may subscribe to mobile service, such as, for example, 3G
mobile service, offered through the mobile operator core network
850. In addition, an access terminal 820 may be capable of
operating both in macro environments and in smaller scale (e.g.,
residential) network environments. In other words, depending on the
current location of the access terminal 820, the access terminal
820 may be served by a macro cell access point 860 associated with
the mobile operator core network 850 or by any one of a set of
femto access points 810 (e.g., the femto access points 810A and
810B that reside within a corresponding user residence 830). For
example, when a subscriber is outside his home, he is served by a
standard macro access point (e.g., access point 860) and when the
subscriber is at home, he is served by a femto access point (e.g.,
access point 810A). Here, a femto access point 810 may be backward
compatible with legacy access terminals 820.
[0090] A femto access point 810 may be deployed on a single
frequency or, in the alternative, on multiple frequencies.
Depending on the particular configuration, the single frequency or
one or more of the multiple frequencies may overlap with one or
more frequencies used by a macro access point (e.g., access point
860).
[0091] In some aspects, an access terminal 820 may be configured to
connect to a preferred femto access point (e.g., the home femto
access point of the access terminal 820) whenever such connectivity
is possible. For example, whenever the access terminal 820A is
within the user's residence 830, it may be desired that the access
terminal 820A communicate only with the home femto access point
810A or 810B.
[0092] In some aspects, if the access terminal 820 operates within
the macro cellular network 850 but is not residing on its most
preferred network (e.g., as defined in a preferred roaming list),
the access terminal 820 may continue to search for the most
preferred network (e.g., the preferred femto access point 810)
using a better system reselection (BSR) procedure, which may
involve a periodic scanning of available systems to determine
whether better systems are currently available and subsequently
acquire such preferred systems. The access terminal 820 may limit
the search for specific band and channel. For example, one or more
femto channels may be defined whereby all femto access points (or
all restricted femto access points) in a region operate on the
femto channel(s). The search for the most preferred system may be
repeated periodically. Upon discovery of a preferred femto access
point 810, the access terminal 820 selects the femto access point
810 and registers on it for use when within its coverage area.
[0093] Access to a femto access point may be restricted in some
aspects. For example, a given femto access point may only provide
certain services to certain access terminals. In deployments with
so-called restricted (or closed) access, a given access terminal
may only be served by the macro cell mobile network and a defined
set of femto access points (e.g., the femto access points 810 that
reside within the corresponding user residence 830). In some
implementations, an access point may be restricted to not provide,
for at least one access point, at least one of: signaling, data
access, registration, paging, or service.
[0094] In some aspects, a restricted femto access point (which may
also be referred to as a Closed Subscriber Group Home NodeB) is one
that provides service to a restricted provisioned set of access
terminals. This set may be temporarily or permanently extended as
necessary. In some aspects, a Closed Subscriber Group (CSG) may be
defined as the set of access points (e.g., femto access points)
that share a common access control list of access terminals.
[0095] Various relationships may thus exist between a given femto
access point and a given access terminal. For example, from the
perspective of an access terminal, an open femto access point may
refer to a femto access point with unrestricted access (e.g., the
femto access point allows access to any access terminal). A
restricted femto access point may refer to a femto access point
that is restricted in some manner (e.g., restricted for access
and/or registration). A home femto access point may refer to a
femto access point on which the access terminal is authorized to
access and operate on (e.g., permanent access is provided for a
defined set of one or more access terminals). A guest (or hybrid)
femto access point may refer to a femto access point on which an
access terminal is temporarily authorized to access or operate on.
An alien femto access point may refer to a femto access point on
which the access terminal is not authorized to access or operate
on, except for perhaps emergency situations (e.g., 911 calls).
[0096] From a restricted femto access point perspective, a home
access terminal may refer to an access terminal that is authorized
to access the restricted femto access point installed in the
residence of that access terminal's owner (usually the home access
terminal has permanent access to that femto access point). A guest
access terminal may refer to an access terminal with temporary
access to the restricted femto access point (e.g., limited based on
deadline, time of use, bytes, connection count, or some other
criterion or criteria). An alien access terminal may refer to an
access terminal that does not have permission to access the
restricted femto access point, except for perhaps emergency
situations, for example, such as 911 calls (e.g., an access
terminal that does not have the authentication information or
permission to register with the restricted femto access point).
[0097] For convenience, the disclosure herein describes various
functionality in the context of a femto access point. It should be
appreciated, however, that a pico access point may provide the same
or similar functionality for a larger coverage area. For example, a
pico access point may be restricted, a home pico access point may
be defined for a given access terminal, and so on.
[0098] The teachings herein may be employed in a wireless
multiple-access communication system that simultaneously supports
communication for multiple wireless access terminals. Here, each
terminal may communicate with one or more access points via
transmissions on the forward and reverse links. The forward link
(or downlink) refers to the communication link from the access
points to the terminals, and the reverse link (or uplink) refers to
the communication link from the terminals to the access points.
This communication link may be established via a
single-in-single-out system, a multiple-in-multiple-out (MIMO)
system, or some other type of system.
[0099] A MIMO system employs multiple (N.sub.T) transmit antennas
and multiple (N.sub.R) receive antennas for data transmission. A
MIMO channel formed by the N.sub.T transmit and N.sub.R receive
antennas may be decomposed into N.sub.S independent channels, which
are also referred to as spatial channels, where
N.sub.S.ltoreq.min{N.sub.T, N.sub.R}. Each of the N.sub.S
independent channels corresponds to a dimension. The MIMO system
may provide improved performance (e.g., higher throughput and/or
greater reliability) if the additional dimensionalities created by
the multiple transmit and receive antennas are utilized.
[0100] A MIMO system may support time division duplex (TDD) and
frequency division duplex (FDD). In a TDD system, the forward and
reverse link transmissions are on the same frequency region so that
the reciprocity principle allows the estimation of the forward link
channel from the reverse link channel. This enables the access
point to extract transmit beam-forming gain on the forward link
when multiple antennas are available at the access point.
[0101] FIG. 10 illustrates a wireless device 1010 (e.g., an access
point) and a wireless device 1050 (e.g., an access terminal) of a
sample MIMO system 1000. At the device 1010, traffic data for a
number of data streams is provided from a data source 1012 to a
transmit (TX) data processor 1014. Each data stream may then be
transmitted over a respective transmit antenna.
[0102] The TX data processor 1014 formats, codes, and interleaves
the traffic data for each data stream based on a particular coding
scheme selected for that data stream to provide coded data. The
coded data for each data stream may be multiplexed with pilot data
using orthogonal frequency division multiplexing (OFDM) techniques.
The pilot data is typically a known data pattern that is processed
in a known manner and may be used at the receiver system to
estimate the channel response. The multiplexed pilot and coded data
for each data stream is then modulated (i.e., symbol mapped) based
on a particular modulation scheme (e.g., binary phase shift keying
(BPSK), quadrature phase shift keying (QSPK), M-ary phase shift
keying (M-PSK), or M-ary quadrature amplitude modulation (M-QAM))
selected for that data stream to provide modulation symbols. The
data rate, coding, and modulation for each data stream may be
determined by instructions performed by a processor 1030. A data
memory 1032 may store program code, data, and other information
used by the processor 1030 or other components of the device
1010.
[0103] The modulation symbols for all data streams are then
provided to a TX MIMO processor 1020, which may further process the
modulation symbols (e.g., for OFDM). The TX MIMO processor 1020
then provides N.sub.T modulation symbol streams to N.sub.T
transceivers (XCVR) 1022A through 1022T. In some aspects, the TX
MIMO processor 1020 applies beam-forming weights to the symbols of
the data streams and to the antenna from which the symbol is being
transmitted.
[0104] Each transceiver 1022 receives and processes a respective
symbol stream to provide one or more analog signals, and further
conditions (e.g., amplifies, filters, and upconverts) the analog
signals to provide a modulated signal suitable for transmission
over the MIMO channel. N.sub.T modulated signals from transceivers
1022A through 1022T are then transmitted from N.sub.T antennas
1024A through 1024T, respectively.
[0105] At the device 1050, the transmitted modulated signals are
received by N.sub.R antennas 1052A through 1052R and the received
signal from each antenna 1052 is provided to a respective
transceiver (XCVR) 1054A through 1054R. Each transceiver 1054
conditions (e.g., filters, amplifies, and downconverts) a
respective received signal, digitizes the conditioned signal to
provide samples, and further processes the samples to provide a
corresponding "received" symbol stream.
[0106] A receive (RX) data processor 1060 then receives and
processes the N.sub.R received symbol streams from N.sub.R
transceivers 1054 based on a particular receiver processing
technique to provide N.sub.T "detected" symbol streams. The RX data
processor 1060 then demodulates, deinterleaves, and decodes each
detected symbol stream to recover the traffic data for the data
stream. The processing by the RX data processor 1060 is
complementary to that performed by the TX MIMO processor 1020 and
the TX data processor 1014 at the device 1010.
[0107] A processor 1070 periodically determines which pre-coding
matrix to use (discussed below). The processor 1070 formulates a
reverse link message comprising a matrix index portion and a rank
value portion. A data memory 1072 may store program code, data, and
other information used by the processor 1070 or other components of
the device 1050.
[0108] The reverse link message may comprise various types of
information regarding the communication link and/or the received
data stream. The reverse link message is then processed by a TX
data processor 1038, which also receives traffic data for a number
of data streams from a data source 1036, modulated by a modulator
1080, conditioned by the transceivers 1054A through 1054R, and
transmitted back to the device 1010.
[0109] At the device 1010, the modulated signals from the device
1050 are received by the antennas 1024, conditioned by the
transceivers 1022, demodulated by a demodulator (DEMOD) 1040, and
processed by a RX data processor 1042 to extract the reverse link
message transmitted by the device 1050. The processor 1030 then
determines which pre-coding matrix to use for determining the
beam-forming weights then processes the extracted message.
[0110] FIG. 10 also illustrates that the communication components
may include one or more components that perform access control
operations as taught herein. For example, an access control
component 1090 may cooperate with the processor 1030 and/or other
components of the device 1010 to send/receive signals to/from
another device (e.g., device 1050) as taught herein. Similarly, an
access control component 1092 may cooperate with the processor 1070
and/or other components of the device 1050 to send/receive signals
to/from another device (e.g., device 1010). It should be
appreciated that for each device 1010 and 1050 the functionality of
two or more of the described components may be provided by a single
component. For example, a single processing component may provide
the functionality of the access control component 1090 and the
processor 1030 and a single processing component may provide the
functionality of the access control component 1092 and the
processor 1070. In some implementations, the processor 1030 and the
memory 1032 may collectively provide access-related and other
functionality as taught herein for the device 1010, and the
processor 1070 and the memory 1072 may collectively provide
access-related and other functionality as taught herein for the
device 1050.
[0111] The teachings herein may be incorporated into various types
of communication systems and/or system components. In some aspects,
the teachings herein may be employed in a multiple-access system
capable of supporting communication with multiple users by sharing
the available system resources (e.g., by specifying one or more of
bandwidth, transmit power, coding, interleaving, and so on). For
example, the teachings herein may be applied to any one or
combinations of the following technologies: Code Division Multiple
Access (CDMA) systems, Multiple-Carrier CDMA (MCCDMA), Wideband
CDMA (W-CDMA), High-Speed Packet Access (HSPA, HSPA+) systems, Time
Division Multiple Access (TDMA) systems, Frequency Division
Multiple Access (FDMA) systems, Single-Carrier FDMA (SC-FDMA)
systems, Orthogonal Frequency Division Multiple Access (OFDMA)
systems, or other multiple access techniques. A wireless
communication system employing the teachings herein may be designed
to implement one or more standards, such as IS-95, cdma2000,
IS-856, W-CDMA, TDSCDMA, and other standards. A CDMA network may
implement a radio technology such as Universal Terrestrial Radio
Access (UTRA), cdma2000, or some other technology. UTRA includes
W-CDMA and Low Chip Rate (LCR). The cdma2000 technology covers
IS-2000, IS-95 and IS-856 standards. A TDMA network may implement a
radio technology such as Global System for Mobile Communications
(GSM). An OFDMA network may implement a radio technology such as
Evolved UTRA (E-UTRA), IEEE 802.11, IEEE 802.16, IEEE 802.20,
Flash-OFDM.RTM., etc. UTRA, E-UTRA, and GSM are part of Universal
Mobile Telecommunication System (UMTS). The teachings herein may be
implemented in a 3GPP Long Term Evolution (LTE) system, an
Ultra-Mobile Broadband (UMB) system, and other types of systems.
LTE is a release of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS
and LTE are described in documents from an organization named "3rd
Generation Partnership Project" (3GPP), while cdma2000 is described
in documents from an organization named "3rd Generation Partnership
Project 2" (3GPP2). Although certain aspects of the disclosure may
be described using 3GPP terminology, it is to be understood that
the teachings herein may be applied to 3GPP (e.g., Re199, Re15,
Re16, Re17) technology, as well as 3GPP2 (e.g., 1.times.RTT,
1.times.EV-DO RelO, RevA, RevB) technology and other
technologies.
[0112] The teachings herein may be incorporated into (e.g.,
implemented within or performed by) a variety of apparatuses (e.g.,
nodes). In some aspects, a node (e.g., a wireless node) implemented
in accordance with the teachings herein may comprise an access
point or an access terminal.
[0113] For example, an access terminal may comprise, be implemented
as, or known as user equipment, a subscriber station, a subscriber
unit, a mobile station, a mobile, a mobile node, a remote station,
a remote terminal, a user terminal, a user agent, a user device, or
some other terminology. In some implementations an access terminal
may comprise a cellular telephone, a cordless telephone, a session
initiation protocol (SIP) phone, a wireless local loop (WLL)
station, a personal digital assistant (PDA), a handheld device
having wireless connection capability, or some other suitable
processing device connected to a wireless modem. Accordingly, one
or more aspects taught herein may be incorporated into a phone
(e.g., a cellular phone or smart phone), a computer (e.g., a
laptop), a portable communication device, a portable computing
device (e.g., a personal data assistant), an entertainment device
(e.g., a music device, a video device, or a satellite radio), a
global positioning system device, or any other suitable device that
is configured to communicate via a wireless medium.
[0114] An access point may comprise, be implemented as, or known as
a NodeB, an eNodeB, a radio network controller (RNC), a base
station (BS), a radio base station (RBS), a base station controller
(BSC), a base transceiver station (BTS), a transceiver function
(TF), a radio transceiver, a radio router, a basic service set
(BSS), an extended service set (ESS), a macro cell, a macro node, a
Home eNB (HeNB), a femto cell, a femto node, a pico node, or some
other similar terminology.
[0115] In some aspects a node (e.g., an access point) may comprise
an access node for a communication system. Such an access node may
provide, for example, connectivity for or to a network (e.g., a
wide area network such as the Internet or a cellular network) via a
wired or wireless communication link to the network. Accordingly,
an access node may enable another node (e.g., an access terminal)
to access a network or some other functionality. In addition, it
should be appreciated that one or both of the nodes may be portable
or, in some cases, relatively non-portable.
[0116] Also, it should be appreciated that a wireless node may be
capable of transmitting and/or receiving information in a
non-wireless manner (e.g., via a wired connection). Thus, a
receiver and a transmitter as discussed herein may include
appropriate communication interface components (e.g., electrical or
optical interface components) to communicate via a non-wireless
medium.
[0117] A wireless node may communicate via one or more wireless
communication links that are based on or otherwise support any
suitable wireless communication technology. For example, in some
aspects a wireless node may associate with a network. In some
aspects the network may comprise a local area network or a wide
area network. A wireless device may support or otherwise use one or
more of a variety of wireless communication technologies,
protocols, or standards such as those discussed herein (e.g., CDMA,
TDMA, OFDM, OFDMA, WiMAX, Wi-Fi, and so on). Similarly, a wireless
node may support or otherwise use one or more of a variety of
corresponding modulation or multiplexing schemes. A wireless node
may thus include appropriate components (e.g., air interfaces) to
establish and communicate via one or more wireless communication
links using the above or other wireless communication technologies.
For example, a wireless node may comprise a wireless transceiver
with associated transmitter and receiver components that may
include various components (e.g., signal generators and signal
processors) that facilitate communication over a wireless
medium.
[0118] The functionality described herein (e.g., with regard to one
or more of the accompanying figures) may correspond in some aspects
to similarly designated "means for" functionality in the appended
claims. Referring to FIGS. 11-14, apparatuses 1100, 1200, 1300, and
1400 are represented as a series of interrelated functional
modules. Here, a first tunnel establishing module 1102, a second
tunnel establishing module 1104, a child security associations
establishing module 1118, a tunnel access request receiving module
1120, an established tunnel determining module 1122, and an access
terminal redirecting module 1124 may correspond at least in some
aspects to, for example, a tunnel controller as discussed herein. A
packet determining module 1106, a received packet forwarding module
1108, an address request sending module 1110, an address receiving
module 1112, an address sending module 1114, an authentication
information receiving module 1116 may correspond at least in some
aspects to, for example, a communication controller as discussed
herein. An access point identifying module 1202 may correspond at
least in some aspects to, for example, a mobility controller as
discussed herein. A security gateway message sending module 1204, a
message response receiving module 1206, a DNS query sending module
1208, and a security gateway address receiving module 1210 may
correspond at least in some aspects to, for example, a
communication controller as discussed herein. A security gateway
address maintaining module 1212 may correspond at least in some
aspects to, for example, a data memory as discussed herein. A
tunnel establishing module 1214 may correspond at least in some
aspects to, for example, a tunnel controller as discussed herein. A
security gateway tunnel establishing module 1302, a child security
associations establishing module 1316, and an access terminal
tunnel establishing module 1318 may correspond at least in some
aspects to, for example, a tunnel controller as discussed herein. A
local network address obtaining module 1304 may correspond at least
in some aspects to, for example, an address controller as discussed
herein. An address message sending module 1306, a packet
transferring module 1308, an address request receiving module 1310,
a packet inspecting module 1312, and a packet forwarding module
1314 may correspond at least in some aspects to, for example, a
communication controller as discussed herein. A first tunnel
establishing module 1402 and a second tunnel establishing module
1406 may correspond at least in some aspects to, for example, a
tunnel controller as discussed herein. An authentication
information obtaining module 1404, a packet receiving module 1412,
a packet inspecting module 1414 and a packet forwarding module 1416
may correspond at least in some aspects to, for example, a
communication controller as discussed herein. A local network
address obtaining module 1408 and an address sending module 1410
may correspond at least in some aspects to, for example, an address
controller as discussed herein. An access point identifying module
1502 may correspond at least in some aspects to, for example, a
mobility controller as discussed herein. A message sending module
1504 may correspond at least in some aspects to, for example, a
communication controller as discussed herein. An access point
identifying module 1602 may correspond at least in some aspects to,
for example, a communication controller as discussed herein. An
identifier storing module 1604 may correspond at least in some
aspects to, for example, a database as discussed herein. A
subscription information using module 1606 may correspond at least
in some aspects to, for example, a database as discussed
herein.
[0119] The functionality of the modules of FIGS. 11-14 may be
implemented in various ways consistent with the teachings herein.
In some aspects the functionality of these modules may be
implemented as one or more electrical components. In some aspects
the functionality of these blocks may be implemented as a
processing system including one or more processor components. In
some aspects the functionality of these modules may be implemented
using, for example, at least a portion of one or more integrated
circuits (e.g., an ASIC). As discussed herein, an integrated
circuit may include a processor, software, other related
components, or some combination thereof. The functionality of these
modules also may be implemented in some other manner as taught
herein. In some aspects one or more of any dashed blocks in FIGS.
11-14 are optional.
[0120] It should be understood that any reference to an element
herein using a designation such as "first," "second," and so forth
does not generally limit the quantity or order of those elements.
Rather, these designations may be used herein as a convenient
method of distinguishing between two or more elements or instances
of an element. Thus, a reference to first and second elements does
not mean that only two elements may be employed there or that the
first element must precede the second element in some manner. Also,
unless stated otherwise a set of elements may comprise one or more
elements. In addition, terminology of the form "at least one of: A,
B, or C" used in the description or the claims means "A or B or C
or any combination of these elements."
[0121] Those of skill in the art would understand that information
and signals may be represented using any of a variety of different
technologies and techniques. For example, data, instructions,
commands, information, signals, bits, symbols, and chips that may
be referenced throughout the above description may be represented
by voltages, currents, electromagnetic waves, magnetic fields or
particles, optical fields or particles, or any combination
thereof.
[0122] Those of skill would further appreciate that any of the
various illustrative logical blocks, modules, processors, means,
circuits, and algorithm steps described in connection with the
aspects disclosed herein may be implemented as electronic hardware
(e.g., a digital implementation, an analog implementation, or a
combination of the two, which may be designed using source coding
or some other technique), various forms of program or design code
incorporating instructions (which may be referred to herein, for
convenience, as "software" or a "software module"), or combinations
of both. To clearly illustrate this interchangeability of hardware
and software, various illustrative components, blocks, modules,
circuits, and steps have been described above generally in terms of
their functionality. Whether such functionality is implemented as
hardware or software depends upon the particular application and
design constraints imposed on the overall system. Skilled artisans
may implement the described functionality in varying ways for each
particular application, but such implementation decisions should
not be interpreted as causing a departure from the scope of the
present disclosure.
[0123] The various illustrative logical blocks, modules, and
circuits described in connection with the aspects disclosed herein
may be implemented within or performed by an integrated circuit
(IC), an access terminal, or an access point. The IC may comprise a
general purpose processor, a digital signal processor (DSP), an
application specific integrated circuit (ASIC), a field
programmable gate array (FPGA) or other programmable logic device,
discrete gate or transistor logic, discrete hardware components,
electrical components, optical components, mechanical components,
or any combination thereof designed to perform the functions
described herein, and may execute codes or instructions that reside
within the IC, outside of the IC, or both. A general purpose
processor may be a microprocessor, but in the alternative, the
processor may be any conventional processor, controller,
microcontroller, or state machine. A processor may also be
implemented as a combination of computing devices, e.g., a
combination of a DSP and a microprocessor, a plurality of
microprocessors, one or more microprocessors in conjunction with a
DSP core, or any other such configuration.
[0124] It is understood that any specific order or hierarchy of
steps in any disclosed process is an example of a sample approach.
Based upon design preferences, it is understood that the specific
order or hierarchy of steps in the processes may be rearranged
while remaining within the scope of the present disclosure. The
accompanying method claims present elements of the various steps in
a sample order, and are not meant to be limited to the specific
order or hierarchy presented.
[0125] In one or more exemplary embodiments, the functions
described may be implemented in hardware, software, firmware, or
any combination thereof. If implemented in software, the functions
may be stored on or transmitted over as one or more instructions or
code on a computer-readable medium. Computer-readable media
includes both computer storage media and communication media
including any medium that facilitates transfer of a computer
program from one place to another. A storage media may be any
available media that can be accessed by a computer. By way of
example, and not limitation, such computer-readable media can
comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage,
magnetic disk storage or other magnetic storage devices, or any
other medium that can be used to carry or store desired program
code in the form of instructions or data structures and that can be
accessed by a computer. Also, any connection is properly termed a
computer-readable medium. For example, if the software is
transmitted from a website, server, or other remote source using a
coaxial cable, fiber optic cable, twisted pair, digital subscriber
line (DSL), or wireless technologies such as infrared, radio, and
microwave, then the coaxial cable, fiber optic cable, twisted pair,
DSL, or wireless technologies such as infrared, radio, and
microwave are included in the definition of medium. Disk and disc,
as used herein, includes compact disc (CD), laser disc, optical
disc, digital versatile disc (DVD), floppy disk and blu-ray disc
where disks usually reproduce data magnetically, while discs
reproduce data optically with lasers. Combinations of the above
should also be included within the scope of computer-readable
media. It should be appreciated that a computer-readable medium may
be implemented in any suitable computer-program product.
[0126] The previous description of the disclosed aspects is
provided to enable any person skilled in the art to make or use the
present disclosure. Various modifications to these aspects will be
readily apparent to those skilled in the art, and the generic
principles defined herein may be applied to other aspects without
departing from the scope of the disclosure. Thus, the present
disclosure is not intended to be limited to the aspects shown
herein but is to be accorded the widest scope consistent with the
principles and novel features disclosed herein.
* * * * *