U.S. patent application number 17/526826 was filed with the patent office on 2022-03-10 for wireless backhaul resiliency.
The applicant listed for this patent is Parallel Wireless, Inc.. Invention is credited to Sumit Garg, Steven Paul Papa.
Application Number | 20220078641 17/526826 |
Document ID | / |
Family ID | 1000005973250 |
Filed Date | 2022-03-10 |
United States Patent
Application |
20220078641 |
Kind Code |
A1 |
Garg; Sumit ; et
al. |
March 10, 2022 |
Wireless Backhaul Resiliency
Abstract
A wireless backhaul resiliency system incorporating a mesh
network is disclosed, comprising: a first base station utilizing a
first mesh network node for a first wide area network
(WAN)/backhaul connection and having a first wireless mesh
functionality; and a second base station utilizing a second mesh
network node for a second WAN/backhaul connection and having a
second wireless mesh functionality, wherein the first base station
is configured to detect when the first WAN/backhaul connection
fails and fail over to a wireless mesh connection between the first
wireless mesh functionality at the first base station and the
second wireless mesh functionality at the second base station,
thereby forwarding data from the first base station to a core
network via the wireless mesh connection, the second mesh network
node, and the second WAN/backhaul connection in the event of a
failure.
Inventors: |
Garg; Sumit; (Hudson,
MA) ; Papa; Steven Paul; (Windham, NH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Parallel Wireless, Inc. |
Nashua |
NH |
US |
|
|
Family ID: |
1000005973250 |
Appl. No.: |
17/526826 |
Filed: |
November 15, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15162593 |
May 23, 2016 |
11178558 |
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17526826 |
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62165458 |
May 22, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 84/12 20130101;
H04B 1/745 20130101; H04W 40/24 20130101; H04W 76/22 20180201; H04L
12/2854 20130101; H04W 88/08 20130101; H04J 11/00 20130101; H04W
24/04 20130101 |
International
Class: |
H04W 24/04 20060101
H04W024/04; H04L 12/28 20060101 H04L012/28; H04J 11/00 20060101
H04J011/00; H04W 76/22 20060101 H04W076/22; H04B 1/74 20060101
H04B001/74 |
Claims
1. A wireless backhaul resiliency system incorporating a mesh
network, comprising: a first base station utilizing a first mesh
network node for a first wide area network (WAN)/backhaul
connection and having a first wireless mesh functionality; and a
second base station utilizing a second mesh network node for a
second WAN/backhaul connection and having a second wireless mesh
functionality, wherein the first base station is configured to
detect when the first WAN/backhaul connection fails and fail over
to a wireless mesh connection between the first wireless mesh
functionality at the first base station and the second wireless
mesh functionality at the second base station, thereby forwarding
data from the first base station to a core network via the wireless
mesh connection, the second mesh network node, and the second
WAN/backhaul connection in the event of a failure, and wherein the
first WAN/backhaul connection is a wired connection.
2. The system of claim 1, wherein the first base station further
comprises a routing functionality configured to install a route to
the core network based on connectivity of a WAN/backhaul
connection.
3. The system of claim 1, wherein the first and the second base
stations are Long Term Evolution (LTE) eNodeBs and wherein the
wireless mesh connection is a Wi-Fi connection.
4. The system of claim 1, wherein the first mesh network node is
colocated with the first base station and wherein the second mesh
network node is colocated with the second base station.
5. The system of claim 1, wherein the first WAN/backhaul connection
and the second WAN/backhaul connection are in communication with
different network interconnection points for communication with the
core network.
6. The system of claim 1, wherein the first and the second base
stations send and receive X2 protocol messages via the wireless
mesh connection between the first wireless mesh functionality at
the first base station and the second wireless mesh functionality
at the second base station without transiting through the core
network.
7. The system of claim 1, wherein the first and the second base
station each further comprise two or more radios for wireless mesh
functionality.
8. The system of claim 1, wherein the first and the second base
station are wirelessly coupled to other mesh nodes in a ring
topology.
9. The system of claim 1, wherein the first mesh network node is
configured to fail over to at least one wireless mesh connection
based on an ordered pre-configured list of wireless mesh
connections.
10. The system of claim 1, wherein the first mesh network node is
configured to fail over to the wireless mesh connection at the
second mesh network node based on a geographic proximity between
the first mesh network node and the second mesh network node.
11. The system of claim 1, wherein the wireless mesh connection is
at least one of an IEEE 802.11a/b/g/n/ac/ad/af/ah Wi-Fi connection,
a microwave connection, a Long Term Evolution (LTE) connection, a
wireless connection with a frequency between 5.0 and 6.0 GHz, a
wireless connection with a frequency between 2.2 and 2.5 GHz, and a
wireless connection with a frequency between 20 and 65 GHz.
12. A method, comprising: sending, from a Long Term Evolution (LTE)
base station, data packets to a core network over a wired backhaul
connection; identifying a failure of the wired backhaul connection
at the LTE base station; setting up a wireless mesh network with
another LTE base station; and re-routing data packets at the LTE
base station to the core network via the wireless mesh network with
the another LTE base station.
13. The method of claim 12, further comprising detecting a
reconnection of the wired backhaul connection at the LTE base
station and re-routing data packets at the LTE base station to the
core network via the wired backhaul connection.
14. The method of claim 12, wherein the wired backhaul connection
and the another LTE base station are in communication with
different network interconnection points for communication with the
core network.
15. The method of claim 12, wherein the LTE base station and the
another LTE base station send and receive X2 protocol messages
between each other via the wireless mesh network.
16. The method of claim 12, wherein the LTE base station and the
another LTE base station are configured with two or more radios for
wireless mesh functionality.
17. The method of claim 12, further comprising the LTE base station
and the another LTE base station wirelessly coupling to other mesh
nodes in a ring topology.
18. The method of claim 12, further comprising the LTE base station
failing over to at least one wireless mesh connection based on an
ordered pre-configured list of wireless mesh connections.
19. The method of claim 12, further comprising the LTE base station
failing over to the another LTE base station based on a geographic
proximity between the LTE base station and the another LTE base
station.
20. The method of claim 12, wherein the wireless mesh network is at
least one of an IEEE 802.11a/b/g/n/ac/ad/af/ah Wi-Fi connection, a
microwave connection, a Long Term Evolution (LTE) connection, a
wireless connection with a frequency between 5.0 and 6.0 GHz, a
wireless connection with a frequency between 2.2 and 2.5 GHz, and a
wireless connection with a frequency between 20 and 65 GHz.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 15/162,593, filed May 23, 2016, which claims the benefit of
priority under 35 U.S.C. .sctn. 119(e) of U.S. Provisional Patent
Application No. 62/165,458, having attorney docket no.
PWS-71828US00, filed on May 22, 2015 and entitled "Wireless
Backhaul Resiliency," each of which is hereby incorporated by
reference in its entirety for all purposes. The present application
also hereby incorporates by reference U.S. patent application Ser.
No. 13/889,631, "Heterogeneous Mesh Network and a Multi-RAT Node
Used Therein," filed May 8, 2013, having attorney docket no.
PWS-71700U501; U.S. patent application Ser. No. 14/024,717,
"Heterogeneous Self-Organizing Network for Access and Backhaul,"
filed Sep. 12, 2013, having attorney docket no. PWS-71700US02; U.S.
patent application Ser. No. 14/183,176, "Methods of incorporating
an Ad Hoc Cellular Network into a Fixed Cellular Network," filed
Feb. 18, 2014, having attorney docket no. PWS-71710US01; U.S.
patent application Ser. No. 14/642,544, "Federated X2 Gateway,"
filed Mar. 9, 2015, having attorney docket no. PWS-71756US01; U.S.
patent application Ser. No. 14/828,432, "Inter-Cell Interference
Mitigation," filed August 17, 2015, having attorney docket no.
PWS-71771US01; and U.S. patent application Ser. No. 15/132,229,
"MaxMesh: Mesh Backhaul Routing," filed Apr. 18, 2016, having
attorney docket no. PWS-71820US01, each in its entirety for all
purposes. Additionally, U.S. Pat. App. Pub. Nos. US20140086120,
US20140092765, US20140133456, US20150045063, and US20150078167 are
hereby incorporated by reference in their entirety for all
purposes.
BACKGROUND
[0002] With the proliferation of mobile devices, a mobile network
is dependent on its backhaul, or connection to a core network.
Currently, macro base stations provide backhaul to attached base
stations via wired or wireless links to upstream nodes. Improving
the resiliency of this backhaul is therefore desirable and useful.
Specifically, macro base stations typically obtain backhaul via a
wired network connection, such as an optical fiber or coaxial
connection to a local Internet point of presence (POP). This
network connection is routed through the infrastructure of the
local Internet POP, which may include, without limitation, routers,
switches, intermediary links, and other network infrastructure. The
Internet POP provides Internet connectivity, which may be used to
provide transport for communications to and from the mobile
operator's core network, and/or dedicated connectivity to the
mobile operator's core network.
[0003] In the event that a failure occurs at the local Internet
POP, the macro base station will lose its connection to the core
network. For example, if an adverse weather event results in
flooding or destruction of the Internet POP's network
infrastructure in a given city, the macro will lose its backhaul
connection. However, it would be helpful for the macro base station
to be enabled to connect to a secondary Internet POP via a
secondary network link, for providing resilient backhaul
infrastructure, i.e., backhaul that is resistant to service
interruptions.
SUMMARY
[0004] In some embodiments, a macro base station is enabled to
share a backhaul connection with another macro base station, using
a wireless backhaul system incorporating a mesh network. A first
macro base station utilizes a first mesh network node for its wide
area network (WAN)/backhaul connection. A second macro base station
also utilizes a second mesh network node for its own WAN/backhaul
connection. If a failure occurs in the backhaul connection for the
first macro base station, the first macro base station may cut over
its backhaul connection to the backhaul connection of the second
macro base station. Data to and from the backhaul connection may be
forwarded from the first mesh network node to the second mesh
network node, thereby providing a secondary backhaul
connection.
[0005] In one embodiment, a wireless backhaul resiliency system
incorporating a mesh network is disclosed, comprising: a first base
station utilizing a first mesh network node for a first wide area
network (WAN)/backhaul connection and having a first wireless mesh
functionality; and a second base station utilizing a second mesh
network node for a second WAN/backhaul connection and having a
second wireless mesh functionality, wherein the first base station
is configured to detect when the first WAN/backhaul connection
fails and fail over to a wireless mesh connection between the first
wireless mesh functionality at the first base station and the
second wireless mesh functionality at the second base station,
thereby forwarding data from the first base station to a core
network via the wireless mesh connection, the second mesh network
node, and the second WAN/backhaul connection in the event of a
failure, and wherein the first WAN/backhaul connection is a wired
connection.
[0006] The first base station may further comprise a routing
functionality configured to install a route to the core network
based on connectivity of a WAN/backhaul connection. The first and
the second base stations may be Long Term Evolution (LTE) eNodeBs
and the wireless mesh connection may be a Wi-Fi connection. The
first mesh network node may be colocated with the first base
station and the second mesh network node may be colocated with the
second base station. The first WAN/backhaul connection and the
second WAN/backhaul connection may be in communication with
different network interconnection points for communication with the
core network. The first and the second base stations may send and
receive X2 protocol messages via the wireless mesh connection
between the first wireless mesh functionality at the first base
station and the second wireless mesh functionality at the second
base station without transiting through the core network. The first
and the second base station may each further comprise two or more
radios for wireless mesh functionality. The first and the second
base station may be wirelessly coupled to other mesh nodes in a
ring topology. The first mesh network node may be configured to
fail over to at least one wireless mesh connection based on an
ordered pre-configured list of wireless mesh connections. The first
mesh network node may be configured to fail over to the wireless
mesh connection at the second mesh network node based on a
geographic proximity between the first mesh network node and the
second mesh network node. The wireless mesh connection may be at
least one of an IEEE 802.11a/b/g/n/ac/ad/af/ah Wi-Fi connection, a
microwave connection, a Long Term Evolution (LTE) connection, a
wireless connection with a frequency between 5.0 and 6.0 GHz, a
wireless connection with a frequency between 2.2 and 2.5 GHz, and a
wireless connection with a frequency between 20 and 65 GHz.
[0007] In another embodiment, a method is disclosed, comprising:
sending, from a Long Term Evolution (LTE) base station, data
packets to a core network over a wired backhaul connection;
identifying a failure of the wired backhaul connection at the LTE
base station; setting up a wireless mesh network with another LTE
base station; and re-routing data packets at the LTE base station
to the core network via the wireless mesh network with the another
LTE base station.
[0008] The method may further comprise detecting a reconnection of
the wired backhaul connection at the LTE base station and
re-routing data packets at the LTE base station to the core network
via the wired backhaul connection. The wired backhaul connection
and the another LTE base station may be in communication with
different network interconnection points for communication with the
core network. The LTE base station and the another LTE base station
may send and receive X2 protocol messages between each other via
the wireless mesh network. The LTE base station and the another LTE
base station may be configured with two or more radios for wireless
mesh functionality. The method may further comprise the LTE base
station and the another LTE base station wirelessly coupling to
other mesh nodes in a ring topology. The method may further
comprise the LTE base station failing over to at least one wireless
mesh connection based on an ordered pre-configured list of wireless
mesh connections. The method may further comprise the LTE base
station failing over to the another LTE base station based on a
geographic proximity between the LTE base station and the another
LTE base station. The wireless mesh network may be at least one of
an IEEE 802.11a/b/g/n/ac/ad/af/ah Wi-Fi connection, a microwave
connection, a Long Term Evolution (LTE) connection, a wireless
connection with a frequency between 5.0 and 6.0 GHz, a wireless
connection with a frequency between 2.2 and 2.5 GHz, and a wireless
connection with a frequency between 20 and 65 GHz.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic diagram of a prior art network
configuration.
[0010] FIG. 2 is a schematic diagram of a resilient wireless
network, in accordance with some embodiments.
[0011] FIG. 3 is a further schematic diagram of a resilient
wireless network, in accordance with some embodiments.
[0012] FIG. 4 is a schematic diagram of an enhanced mesh base
station, in accordance with some embodiments.
[0013] FIG. 5 is a schematic diagram of a signaling coordinator, in
accordance with some embodiments.
DETAILED DESCRIPTION
[0014] In current macro deployments, the backhaul interface is
typically a wired network interface connecting the base station to
the network, variously referred to herein as a wide area network
(WAN) or operator network, with each base station having its own
such wired backhaul connection using, e.g., a fiber optic or
Ethernet connection. Secondary interfaces may also be set up as
wired network interfaces in the same manner. However, it is
expensive to set up and maintain multiple wired backhaul
connections, with one being a backup or secondary interface. As
well, a secondary interface will typically plug into the network at
the same physical location, which may be a switch in a network
closet connected to the WAN. When this interconnection point is the
same as the primary interface, the secondary interface remains
vulnerable to many of the issues that may cause network failure.
For example, the network switch being used as the endpoint of the
wired backhaul connection, or another network device in the chain
of devices between the base station and the operator core network
may fail or lose power. Since the secondary backhaul connection is
connected to the same network device, the redundancy of the
secondary interface is defeated by this type of network equipment
fault.
[0015] A system is proposed wherein a wireless network is used to
provide resilient backhaul for a radio tower or base station. A
mesh network node, which may be a mesh base station or a
multi-radio access technology (multi-RAT) node, may be situated in
a network behind a cellular base station and in front of a core
network. The mesh network nodes may provide backhaul capability for
the cellular base station when a primary network link of the
cellular base station fails. This approach handles localized
outages on the WAN or connectivity for macro. Instead of using a
single point of interconnection for the backhaul connection, the
base station uses a wireless connection with a second base station,
and shares the second base station's backhaul connection. The
second base station is connected to the core network at a separate
network interconnect. The secondary backhaul connection thus has
the advantage of not being connected to the same secondary network
link as the first macro cell. As an example, the second base
station may be located in another city, and may utilize a different
Internet service provider point-of-presence (ISP POP). This enables
greater resiliency over the common case of having the secondary
connection use the same interconnection point.
[0016] The wireless connection with the second base station may be
enabled using a mesh network. Each base station may be equipped
with a colocated mesh network node, and each mesh network node may
be configured to connect to one or more other nodes in the mesh
network via a wireless connection. The mesh network nodes may use
their direct wireless links to enable communication between the
base stations. For example, for two LTE eNodeBs, the wireless
interface may be kept active and may be used for exchanging X2
protocol messages according to 3GPP specifications. Alternatively,
the wireless interface may be brought up and down on an as-needed
basis. The direct wireless links may also provide a secondary
backhaul connection to be used when the primary backhaul connection
fails.
[0017] In normal operation, user data may be received at the base
station and may be transmitted via a wired backhaul interface to a
first network interconnect for the first node, and to a second
network interconnect for the second node. Once the first base
station identifies a failure, the first base station activates the
secondary wireless interface for backup operation. The mesh base
station calculates updated routes, such as an updated default route
that uses the wireless interface, and then directs traffic over the
wireless interface. In many cases only minimal interruptions in
service may occur. The mesh base station may continue to monitor
the wired backhaul interface and may switch the default route back
to it when it is reactivated.
[0018] Even if the wireless link is slightly degraded compared with
the wired link, the link may be used to throttle services or to
inform the core network that only limited service is available.
[0019] This approach has several advantages. The use of a mesh
network, with point-to-point links, makes backup connectivity to
the core network as simple as establishing another point-to-point
wireless link. Multiple radios may be present on the mesh network
node, and may enable the base station to select a particular mesh
node to connect to for its secondary link based on various factors.
The use of a different interconnection point in the network helps
get around localized outages. As well, X2 flows can be enhanced by
delivering the X2 messages over the direct wireless links, instead
of sending an X2 message from a source base station to the core
network for delivery back to the target base station. In some
embodiments, X2 protocol messages may be routed over a shortest
path.
[0020] These advantages may be obtained without significantly
increasing latency, by utilizing a sufficiently fast processor for
performing routing computation for sub-second routing convergence
at a routing module in the mesh base station. In some embodiments,
convergence may be configurable, and may be configured to be a
value between 800 ms and 2 seconds, in some embodiments. In some
embodiments no buffering beyond underlying protocol buffering may
be used.
[0021] When multiple mesh nodes are available for establishment of
a wireless interface, the establishment of the wireless interface
can be based on received information about the status or load or
active state of the wireless link endpoint. Alternatively, the mesh
network node may be configured with a particular order of nodes to
try, or the mesh network node may be configured to attempt to
connect to a mesh network node outside of its immediate geographic
vicinity using, e.g., stored global positioning system (GPS)
coordinates.
[0022] The mesh network may use a Wi-Fi interface, such as a 2.4
GHz or 5.X GHz connection, or another wireless interface as
described herein. The second base station's backhaul connection may
be wired or wireless. The mesh base stations may be part of the
same physical device as the base stations, which may be LTE eNodeBs
or UMTS nodeBs. The mesh network nodes may include a routing
module, for sending traffic to either a wireless interface or a
wired backhaul connection, and an interface monitoring module, for
detecting when a particular connection, such as a wired backhaul
connection, goes down or comes back up. Colocation has the
advantage that additional points of failure are not introduced into
the system.
[0023] In some embodiments, the mesh network may involve nodes that
are not colocated with the base stations but instead are connected
via a WAN interface, via Ethernet or fiber or another wired
interface with one or more base stations, as shown. In some
embodiments, a mesh network may not be needed and a single wireless
interface may be established between two dedicated network nodes.
In some embodiments, an eNodeB or other base station may connect to
a device specifically configured to activate a wireless mesh link,
and the base station may provide the routing capability needed to
switch between the mesh link and a wired backhaul link.
[0024] In some embodiments a plurality of base stations may be
equipped with the mesh network nodes. It is understood that each
mesh node adds to the resiliency of the system. In some embodiments
a mesh network node or nodes may be equipped with a plurality of
radio interfaces. In some embodiments, the mesh nodes may be
connected in various topologies. For example, the mesh base
stations may have two wireless interfaces, enabling them to form a
ring topology with other similarly-equipped mesh base stations, or
three wireless interfaces, configured to form a more complex
topology. In some embodiments at least two wireless radios per mesh
node may be used. Multiple links to peers may be used for both
resiliency and reduced X2 interface latency, useful for inter-cell
interference cancellation (ICIC).
[0025] Modules as described herein may be software routines or
hardware devices, or hardware configured with software, or both.
Wireless interfaces as described herein may be IEEE
802.11a/b/g/n/ac/ad/af/ah, microwave, 5.4 GHz, 5.8 GHz, 2.3 GHz,
2.4 GHz, 2.6 GHz, 3.5 GHz, 20 GHz, 60 GHz, television whitespace
(TVWS), the international industrial, scientific and medical (ISM)
frequency bands, licensed or non-licensed bands, non-line of sight
or near-line of sight, line-of-sight, or another type of wireless
interface. An LTE network interface and/or UMTS network interface
may be used as the wireless interface, in some embodiments. An
appropriate frequency could be identified based on the
characteristics of that geographic location, either via central
planning or using a radio sniffing capability at the mesh base
station.
[0026] Assuming that a 5.8 GHz band is used, with an output gain of
36 dBm equivalent isotropically radiated power (EIRP) and an
antenna gain from 18 to 25, peak modulation and throughput for 40
MHz of bandwidth is achievable at a distance of between 4.6 and
23.1 km. Adding a 5 dB padding factor to compensate for weather
and/or fading results in a reduction in distance of roughly half.
200 Mbps of data throughput would be available using such a
wireless interface, which would be more than sufficient for
backhauling a typical base station, which can use from 30-35 Mbps
in some use caes.
[0027] In some embodiments, a base station may connect to multiple
peers for both increasing resiliency and reducing X2 interface
latency, thereby improving performance of X2 for providing
inter-cell interference cancellation (ICIC). The base station may
include edge router functionality.
[0028] In some embodiments, synchronization hardware may be
included in the mesh nodes/multi-RAT base stations. The nodes may
then be able to synchronize with each other to attain a high degree
of synchronization. Current synchronization solutions use Global
Positioning System (GPS) or IEEE 1588 Precision Time Protocol (PTP)
technologies to provide synchronization at or above the sync
requirements of 3GPP technologies, e.g., LTE or UMTS. However, PTP
requires a low-latency connection to a time server, which could be
severed in case of a link failure, and GPS requires line-of-sight
to GPS satellites and cannot be used indoors, as well as being
sensitive to jamming. The inclusion of other synchronization
hardware may provide the required synchronization capability
necessary to support LTE communications. An example of such
synchronization hardware is found at, e.g., U.S. Pat. No.
9,048,979, which is hereby incorporated by reference herein in its
entirety for all purposes.
[0029] FIG. 1 is a schematic diagram of a prior art network
configuration. Mobile devices 102 and 103, which may be Long Term
Evolution (LTE) user equipments (UEs), are connected via wireless
connections 104 and 105 to a base station 106. Base station 106 may
be a macro cell and may provide wireless access to a large number
of wireless users, requiring a significant amount of bandwidth to
backhaul the data from the users to the core network. The data to
and from the wireless users may be transferred across wide area
network (WAN) connection 110 and network 120 to core network 130.
In some cases network 120 may be a wireless operator network, and
in other cases may include the public Internet. Core network 130
includes network elements used to provide services to the wireless
users, via base station 106. WAN connection 110 is required in
order to provide service, and when it fails, no secondary backhaul
network is available. In alternate scenarios, WAN connection 110
may include several wired network connections, but as they all
transit through network 120 at a single network interconnection
point (not shown), base station 106 is still vulnerable to attack
or disruption of service.
[0030] FIG. 2 is a schematic diagram of a resilient wireless
network, in accordance with some embodiments. UEs 203 and 204
connect to base stations 206 and 207 using wireless connections,
such as LTE wireless connections. Base stations 206 and 207 are in
communication via WAN connections 210 and 211, respectively, to
mesh network nodes 214 and 216. Mesh network nodes 214 and 216 are
in communication via WAN connections 212 and 213, respectively, to
network interconnect 222 and network interconnect 223,
respectively. Network interconnects 222 and 223 are part of but
separate from network 220 and are in communication with core
network 230. In some embodiments in which mesh nodes 214 and 215
are colocated with base stations 206 and 207, WAN interfaces 210
and 211 may be omitted.
[0031] In normal operation, UE 202 can complete a call via core
network 230 to UE 203. Data for the call flows according to arrows
217 via base station 206, WAN connection 210, mesh base station
214, WAN connection 212, and network interconnect 222 to core
network 230, after which call accounting is performed and a call is
completed with UE 203 via network interconnect 223, WAN connection
213, mesh node 215, WAN connection 211, base station 207 and
wireless connection 205.
[0032] Further, mesh nodes 214 and 216 are in direct communication
via a wireless link between the two nodes. The WAN connections 210,
212, 211, 213 shown are higher bandwidth fixed lines and are
considered the primary backhaul links for base stations 206 and
207. Connection 216 between mesh nodes 214 and 215 may be brought
up and down as needed but is not necessary for operation of the
cells. X2 communications may be sent and received via link 216.
These X2 communications are communications according to the 3GPP X2
protocol between base stations 206 and 207, for example, for
performing inter-cell interference coordination (ICIC) or handover
data redirection. Core network 230 need not be part of the X2
communications because a direct link is available between mesh
nodes 214 and 215.
[0033] FIG. 3 is a further schematic diagram of a resilient
wireless network, in accordance with some embodiments. FIG. 3 shows
a state of the wireless network of FIG. 2 after a network fault has
occurred at WAN connection 312. This may have been, for example,
due to a physical cable being severed, or due to an electrical
fault, or due to a component failure at network interconnect 222.
However, mesh node 314 identifies that WAN connection 312 is not
available, and reroutes data according to arrows 317 across
wireless connection 316 to mesh node 315. If wireless connection
316 is not available, mesh node 314 may direct mesh node 315 to
activate the connection. The failover is transparent to UEs 202 and
203, as well as to base stations 206 and 207.
[0034] Mesh node 314 may select from one or more wireless
connections, in some embodiments, based on its configuration
parameters and in some cases based on observed or measured
information about the quality of links to other nodes in the mesh.
Mesh node 314 may perform routing and/or identification of a
suitable mesh node in conjunction with mesh node 315, another mesh
node, or with core network 230 (in cases when connectivity is still
available), such as with a core network node 500 as shown in FIG.
5. Configuration for mesh node 314 and for failover procedures may
be sent to mesh node 314 from core network 230, including from core
network node 500. Configuration may include routing rules, failover
time thresholds, network interface polling times, preconfigured
latencies and other route information for different wireless mesh
links, information about network functionalities (e.g., frequencies
and wireless protocols) supported by particular mesh nodes, and any
other networking, routing, or operational instructions and data.
Mesh node 315 may also be reconfigured to redirect data flow 317 to
core network 230. In some embodiments no reconfiguration of mesh
node 315 may be necessary (for example, if mesh node 315 is
configured indicating WAN connection 313 as the default route).
[0035] As shown in FIG. 3, wireless interface 316 is now being used
for backhaul by both base station 206 and base station 207. Calls
to and from UE 202 go to the core network 230 via mesh node 315,
WAN connection 313, and network interconnect 223. Calls to and from
UE 203 also go along at least part of the same route, namely, mesh
node 315 and WAN connection 313. X2 messages continue to be sent
along wireless link 316, in addition to all backhauled data from
base station 206.
[0036] At a later time, if WAN connection 312 comes back up, mesh
noe 314 may detect that the connection is now available and may
reactivate that link and may optionally also deactivate wireless
link 316.
[0037] FIG. 4 is a schematic diagram of an enhanced base station,
in accordance with some embodiments. Enhanced base station 400 may
be an eNodeB for use with LTE, and may include processor 402,
processor memory 404 in communication with the processor, baseband
processor 406, and baseband processor memory 408 in communication
with the baseband processor. Enhanced eNodeB 400 may also include
first radio transceiver 410 and second radio transceiver 412,
internal universal serial bus (USB) port 416, and subscriber
information module card (SIM card) 418 coupled to USB port 414. In
some embodiments, the second radio transceiver 412 itself may be
coupled to USB port 416, and communications from the baseband
processor may be passed through USB port 416.
[0038] Processor 402 and baseband processor 406 are in
communication with one another. Processor 402 may perform routing
functions, and may determine if/when a switch in network
configuration is needed, such as when a prior network interface or
network route to a core network becomes disabled and a new mesh
network interface should be configured as a default route. Baseband
processor 406 may generate and receive radio signals for both radio
transceivers 410 and 412, based on instructions from processor 402.
In some embodiments, processors 402 and 406 may be on the same
physical logic board. In other embodiments, they may be on separate
logic boards. In some embodiments, a wired network interface may
also be provided, shown as Ethernet module 440. The wired interface
may be used for connection to a co-located base station, in some
embodiments, or the co-located base station may be provided as part
of base station 400. The wired interface may be used for connection
to a core network via a fiber optic or Ethernet WAN connection, in
some embodiments.
[0039] The first radio transceiver 410 may be a radio transceiver
capable of providing LTE eNodeB functionality, and may be capable
of higher power and multi-channel OFDMA. The second radio
transceiver 412 may be a radio transceiver capable of providing LTE
UE functionality. Both transceivers 410 and 412 are capable of
receiving and transmitting on one or more LTE bands. In some
embodiments, either or both of transceivers 410 and 412 may be
capable of providing both LTE eNodeB and LTE UE functionality.
Transceiver 410 may be coupled to processor 402 via a Peripheral
Component Interconnect-Express (PCI-E) bus, and/or via a
daughtercard. As transceiver 412 is for providing LTE UE
functionality, in effect emulating a user equipment, it may be
connected via the same or different PCI-E bus, or by a USB bus, and
may also be coupled to SIM card 418.
[0040] SIM card 418 may provide information required for
authenticating the simulated UE to the evolved packet core (EPC).
When no access to an operator EPC is available, local EPC 420 may
be used, or another local EPC on the network may be used. This
information may be stored within the SIM card, and may include one
or more of an international mobile equipment identity (IMEI),
international mobile subscriber identity (IMSI), or other parameter
needed to identify a UE. Special parameters may also be stored in
the SIM card or provided by the processor during processing to
identify to a target eNodeB that device 400 is not an ordinary UE
but instead is a special UE for providing backhaul to device
400.
[0041] Wired backhaul or wireless backhaul, or both, may be used
either as primary or secondary. Wired backhaul may be an
Ethernet-based backhaul (including Gigabit Ethernet), or a
fiber-optic backhaul connection, or a cable-based backhaul
connection, in some embodiments. Additionally, wireless backhaul
may be provided in addition to wireless transceivers 410 and 412,
which may be Wi-Fi 402.11a/b/g/n/ac/ad/ah, Bluetooth, ZigBee,
microwave (including line-of-sight microwave), or another wireless
backhaul connection. Any of the wired and wireless connections may
be used for either access or backhaul, according to identified
network conditions and needs, and may be under the control of
processor 402 for reconfiguration. The wireless interface may be
used to create a mesh network with other base stations, including
for the purpose of providing a wireless backhaul connection as
described herein.
[0042] Other elements and/or modules may also be included, such as
a home eNodeB, a local gateway (LGW), a self-organizing network
(SON) module, or another module. Additional radio amplifiers, radio
transceivers and/or wired network connections may also be included.
The SON module may be configured to provide transmit power
increase/decrease functionality, radio band switching
functionality, or communications with another remote SON module
providing, for example, these types of functionality, in some
embodiments. The SON module may be used to perform the steps
described herein and may execute on the general purpose processor
402.
[0043] Processor 402 may identify the appropriate network
configuration, and may perform routing of packets from one network
interface to another accordingly. Processor 402 may use memory 404,
in particular to store a routing table and/or routing rules to be
used for routing packets. Baseband processor 406 may perform
operations to generate the radio frequency signals for transmission
or retransmission by both transceivers 410 and 412. Baseband
processor 406 may also perform operations to decode signals
received by transceivers 410 and 412. Baseband processor 406 may
use memory 408 to perform these tasks.
[0044] FIG. 5 is a schematic diagram of a signaling coordinator
server, in accordance with some embodiments. Signaling coordinator
500 includes processor 502 and memory 504, which are configured to
provide the functions described herein. Also present are radio
access network coordination/signaling (RAN Coordination and
signaling) module 506, RAN proxying module 508, and routing
virtualization module 510. In some embodiments, coordinator server
500 may coordinate multiple RANs using coordination module 506. In
some embodiments, coordination server may also provide proxying,
routing virtualization and RAN virtualization, via modules 510 and
508. In some embodiments, a downstream network interface 512 is
provided for interfacing with the RANs, which may be a radio
interface (e.g., LTE), and an upstream network interface 514 is
provided for interfacing with the core network, which may be either
a radio interface (e.g., LTE) or a wired interface (e.g.,
Ethernet). Signaling storm reduction functions may be performed in
module 506.
[0045] Signaling coordinator 500 includes local evolved packet core
(EPC) module 520, for authenticating users, storing and caching
priority profile information, and performing other EPC-dependent
functions when no backhaul link is available. Local EPC 520 may
include local HSS 522, local MME 524, local SGW 526, and local PGW
528, as well as other modules. Local EPC 520 may incorporate these
modules as software modules, processes, or containers. Local EPC
520 may alternatively incorporate these modules as a small number
of monolithic software processes. Modules 506, 508, 510 and local
EPC 520 may each run on processor 502 or on another processor, or
may be located within another device.
[0046] In some embodiments, the radio transceivers described herein
may be base stations compatible with a Long Term Evolution (LTE)
radio transmission protocol or air interface. The LTE-compatible
base stations may be eNodeBs. In addition to supporting the LTE
protocol, the base stations may also support other air interfaces,
such as UMTS/HSPA, CDMA/CDMA2000, GSM/EDGE, GPRS, EVDO, other
5G/2G, legacy TDD, or other air interfaces used for mobile
telephony. In some embodiments, the base stations described herein
may support Wi-Fi air interfaces, which may include one or more of
IEEE 802.11a/b/g/n/ac/af/p/h. In some embodiments, the base
stations described herein may support IEEE 802.16 (WiMAX), to LTE
transmissions in unlicensed frequency bands (e.g., LTE-U, Licensed
Access or LA-LTE), to LTE transmissions using dynamic spectrum
access (DSA), to radio transceivers for ZigBee, Bluetooth, or other
radio frequency protocols, or other air interfaces. In some
embodiments, the base stations described herein may use
programmable frequency filters. In some embodiments, the Wi-Fi
frequency bands described herein may be channels determined by the
respective IEEE 802.11 protocols, which are incorporated herein to
the maximum extent permitted by law. In some embodiments, the base
stations described herein may provide access to land mobile radio
(LMR)-associated radio frequency bands. In some embodiments, the
base stations described herein may also support more than one of
the above radio frequency protocols, and may also support transmit
power adjustments for some or all of the radio frequency protocols
supported. The embodiments disclosed herein can be used with a
variety of protocols so long as there are contiguous frequency
bands/channels. Although the method described assumes a single-in,
single-output (SISO) system, the techniques described can also be
extended to multiple-in, multiple-out (MIMO) systems.
[0047] Those skilled in the art will recognize that multiple
hardware and software configurations may be used depending upon the
access protocol, backhaul protocol, duplexing scheme, or operating
frequency band by adding or replacing daughtercards to the dynamic
multi-RAT node. Presently, there are radio cards that can be used
for the varying radio parameters. Accordingly, the multi-RAT nodes
of the present invention may be designed to contain as many radio
cards as desired given the radio parameters of heterogeneous mesh
networks within which the multi-RAT node is likely to operate.
Those of skill in the art will recognize that, to the extent an
off-the shelf radio card is not available to accomplish
transmission/reception in a particular radio parameter, a radio
card capable of performing, e.g., in white space frequencies, would
not be difficult to design.
[0048] Those of skill in the art will also recognize that hardware
may embody software, software may be stored in hardware as
firmware, and various modules and/or functions may be performed or
provided either as hardware or software depending on the specific
needs of a particular embodiment.
[0049] Although the scenarios for interference mitigation are
described in relation to macro cells and micro cells, or for a pair
of small cells or pair of macro cells, the same techniques may be
used for reducing interference between any two cells, in which a
set of cells is required to perform the CoMP methods described
herein. The applicability of the above techniques to one-sided
deployments makes them particularly suitable for heterogeneous
networks, including heterogeneous mesh networks, in which all
network nodes are not identically provisioned.
[0050] In any of the scenarios described herein, where processing
may be performed at the cell, the processing may also be performed
in coordination with a cloud coordination server. The eNodeB may be
in communication with the cloud coordination server via an X2
protocol connection, or another connection. The eNodeB may perform
inter-cell coordination via the cloud communication server, when
other cells are in communication with the cloud coordination
server. The eNodeB may communicate with the cloud coordination
server to determine whether the UE has the ability to support a
handover to Wi-Fi, e.g., in a heterogeneous network.
[0051] Although the methods above are described as separate
embodiments, one of skill in the art would understand that it would
be possible and desirable to combine several of the above methods
into a single embodiment, or to combine disparate methods into a
single embodiment. For example, all of the above methods may be
combined. In the scenarios where multiple embodiments are
described, the methods may be combined in sequential order, in
various orders as necessary.
[0052] Although certain of the above systems and methods for
providing interference mitigation are described in reference to the
Long Term Evolution (LTE) standard, one of skill in the art would
understand that these systems and methods may be adapted for use
with other wireless standards or versions thereof.
[0053] In some embodiments, the software needed for implementing
the methods and procedures described herein may be implemented in a
high level procedural or an object-oriented language such as C,
C++, C#, Python, Java, or Perl. The software may also be
implemented in assembly language if desired. Packet processing
implemented in a network device can include any processing
determined by the context. For example, packet processing may
involve high-level data link control (HDLC) framing, header
compression, and/or encryption. In some embodiments, software that,
when executed, causes a device to perform the methods described
herein may be stored on a computer-readable medium such as
read-only memory (ROM), programmable-read-only memory (PROM),
electrically erasable programmable-read-only memory (EEPROM), flash
memory, or a magnetic disk that is readable by a general or special
purpose-processing unit to perform the processes described in this
document. The processors can include any microprocessor (single or
multiple core), system on chip (SoC), microcontroller, digital
signal processor (DSP), graphics processing unit (GPU), or any
other integrated circuit capable of processing instructions such as
an x86 microprocessor.
[0054] Although the present disclosure has been described and
illustrated in the foregoing example embodiments, it is understood
that the present disclosure has been made only by way of example,
and that numerous changes in the details of implementation of the
disclosure may be made without departing from the spirit and scope
of the disclosure, which is limited only by the claims which
follow. Various components in the devices described herein may be
added, removed, or substituted with those having the same or
similar functionality. Various steps as described in the figures
and specification may be added or removed from the processes
described herein, and the steps described may be performed in an
alternative order, consistent with the spirit of the invention.
Features of one embodiment may be used in another embodiment. Other
embodiments are within the following claims.
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