U.S. patent application number 12/862512 was filed with the patent office on 2011-03-10 for single radio wimax interworking.
Invention is credited to PUNEET K. JAIN, POUYA TAAGHOL, XIANGYING YANG.
Application Number | 20110058531 12/862512 |
Document ID | / |
Family ID | 43605315 |
Filed Date | 2011-03-10 |
United States Patent
Application |
20110058531 |
Kind Code |
A1 |
JAIN; PUNEET K. ; et
al. |
March 10, 2011 |
SINGLE RADIO WIMAX INTERWORKING
Abstract
In some embodiments a method comprises establishing a layer 2
tunnel between a mobile station coupled to a E-UTRAN and a WiMAX
base station, implementing a first signaling interface through the
layer 2 tunnel between a mobility management entity (MME) and the
WiMAX base station, and preregistering the mobile station with the
WiMAX access service network gateway at least in part via the layer
2 tunnel. Other embodiments may be described.
Inventors: |
JAIN; PUNEET K.; (HILLSBORO,
OR) ; YANG; XIANGYING; (Portland, OR) ;
TAAGHOL; POUYA; (San Jose, CA) |
Family ID: |
43605315 |
Appl. No.: |
12/862512 |
Filed: |
August 24, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61275266 |
Aug 24, 2009 |
|
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Current U.S.
Class: |
370/331 ;
370/329; 370/338 |
Current CPC
Class: |
G08C 2201/41 20130101;
H04W 72/085 20130101; H04W 8/26 20130101; H04M 7/0069 20130101;
G08C 17/02 20130101; H04W 88/06 20130101; H04W 72/0453 20130101;
H04W 80/04 20130101; Y02D 30/70 20200801; H04L 61/2015 20130101;
H04W 72/042 20130101 |
Class at
Publication: |
370/331 ;
370/338; 370/329 |
International
Class: |
H04W 36/00 20090101
H04W036/00; H04W 60/00 20090101 H04W060/00; H04W 72/04 20090101
H04W072/04 |
Claims
1. A method, comprising: establishing a layer 2 tunnel between a
mobile station coupled to a E-UTRAN and a WiMAX base station;
implementing a first signaling interface through the layer 2 tunnel
between a mobility management entity (MME) and the WiMAX base
station; and preregistering the mobile station with the WiMAX
access service network gateway at least in part via the layer 2
tunnel.
2. The method of claim 1, further comprising maintaining the layer
2 tunnel after the mobile station is preregistered with the WiMAX
access service network gateway.
3. The method of claim 1, further comprising implementing a second
signaling interface between a serving gateway and the WiMAX access
service network gateway.
4. The method of claim 3, wherein: the first signaling interface is
an S101 signaling interface; and the second signaling interface is
an S103 signaling interface.
5. The method of claim 1, wherein preregistering a mobile station
with the WiMAX access service network gateway at least in part via
the layer 2 tunnel comprises at least one of: negotiating one or
more capabilities of the mobile station; authenticating the mobile
station; and establishing a data path for communication between the
mobile station and the WiMAX base station.
6. The method of claim 5, further comprising maintaining context
information for the mobile station after the mobile station has
preregistered with the WiMAX access service network gateway.
7. The method of claim 1, further comprising: receiving a handover
request from the mobile station via the layer 2 tunnel to allocate
resources in a WiMAX access network for the mobile station; and in
response to the request: allocating resources in the WiMAX access
network; and coupling the mobile station to the WiMAX base
station.
8. The method of claim 7, further comprising maintaining the layer
2 tunnel after the mobile station is coupled to the WiMAX base
station.
9. The method of claim 7, further comprising releasing resources
associated with the 3GPP access network after the mobile station is
coupled to the WiMAX base station.
10. The method of claim 9, further comprising updating a state
machine for the mobile station when the mobile station is coupled
to the WiMAX base station.
11. The method of claim 8, further comprising: receiving a handover
request from the mobile station via the layer 2 tunnel to implement
a handover from the WiMAX network to the 3GPP network; and in
response to the request: coupling the mobile station to the 3GPP
network; and releasing resources in the WiMAX network.
12. The method of claim 10, further comprising updating a state
machine for the mobile station when the mobile station is coupled
to the 3GPP network.
13. A method to manage interworking between a WiMAX network and a
3GPP network, comprising: establishing a layer 2 tunnel between a
mobile station coupled to E-UTRAN and a WiMAX base station;
transmitting signaling between the mobile station and the WiMAX
base station through an S101 signaling interface in the layer 2
tunnel.
14. The method of claim 13, wherein the layer 2 tunnel is
established prior to implementing a preregistration process to
preregister the mobile station with a WiMAX access service network
gateway.
15. The method of claim 14, further comprising transmitting
signaling between the WiMAX access service network gateway and a
serving gateway through an S103 signaling interface.
16. The method of claim 13, further comprising preregistering the
mobile station with the WiMAX access service network gateway at
least in part via the layer 2 tunnel.
17. The method of claim 16, further comprising: receiving a
handover request from the mobile station via the layer 2 tunnel to
allocate resources in a WiMAX access network for the mobile
station; and in response to the request: allocating resources in
the WiMAX access network; and coupling the mobile station to the
WiMAX base station.
Description
RELATED APPLICATIONS
[0001] This application claims the right of priority under 35
U.S.C. .sctn.119(e) from U.S. provisional patent application No.
61/275,266, filed Aug. 24, 2009, the disclosure of which is
incorporated herein by reference in its entirety.
BACKGROUND
[0002] Mobile services providers may operate multiple heterogeneous
access technologies and networks. Worldwide Interoperability for
Microwave Access (WiMAX) is a wireless communication access
technology intended to be deployed in accordance with the Institute
of Electrical and Electronics Engineers (IEEE) standard referred to
as IEEE 802.16. WiMAX networks provide broadband wireless
communication over distances which are relatively long. Initial
WiMAX deployment may cover only limited areas of service that may
already be serviced by the third generation (3G) type cellular
networks, such as promulgated by the 3rd Generation Partnership
Project (3GPP). Thus, at least during initial deployment of WiMAX
networks, islands of WiMAX coverage areas may exist within cellular
3G coverage areas. Hence, it may be useful for a 3G network service
provider that deploys WiMAX services to converge WiMAX access and
3G access with seamless vertical mobility, or interaccess.
Furthermore, dual mode devices that are capable of communicating
with both 3G networks and WiMAX networks are expected to be
deployed.
[0003] Current solutions for network interaccess in 3GPP standards
and the cellular industry utilize Layer 3 (L3) protocols (i.e.,
client-based Mobile IP) for providing mobility between access
technologies. However, such L3 protocol-based methods require
simultaneous radio operation of both access technologies to execute
a handover operation between a 3GPP network and a WiMAX network.
Further, client-based Mobile IP techniques may experience
significant latency in performing interaccess handovers that could
hinder operation of real-time services such as Voice over Internet
Protocol (VoIP) applications or the like.
[0004] Protocols have been developed in WiMAX to provide for
single-radio handover between a WiMAX network and a 3GPP network.
In single-radio handovers various network elements cooperate to
manage the handover process between heterogeneous access
networks.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The detailed description is described with reference to the
accompanying figures.
[0006] FIG. 1 is a schematic illustration of a handover between two
or more heterogeneous wireless networks, according to some
embodiments.
[0007] FIG. 2 is a schematic illustration of a network reference
model for single radio interworking of a mobile WiMAX system with a
3GPP access network, according to embodiments.
[0008] FIG. 3 is a schematic illustration of an electronic device
which may be used to implement one or more network nodes in a
wireless network.
[0009] FIG. 4 is a flow diagram illustrating operations in a method
to preregister a mobile station with a WiMAX network, according to
embodiments.
[0010] FIG. 5 is a flow diagram illustrating operations in a method
to implement a handover from a 3GPP access network to a WiMAX
access network, according to some embodiments.
[0011] FIG. 6 is a flow diagram illustrating operations in a method
to implement a handover from a WiMAX access network to a 3GPP
access network, according to some embodiments.
[0012] FIG. 7 is a schematic illustration of a state machine for a
dual mode 3GPP LTE and WiMAX mobile station, according to
embodiments.
[0013] FIG. 8 is a schematic illustration of a data structure which
may be used to convey capability information, according to
embodiments.
[0014] FIG. 9 is a schematic illustration of a broadcast data
structure, according to embodiments.
[0015] FIG. 10 is a flow diagram illustrating operations in an RRC
procedure, according to embodiments.
DETAILED DESCRIPTION
[0016] Described herein are exemplary methods and network nodes
which provides for single radio handover between heterogeneous
networks, e.g., between a 3GPP access network and a WiMAX access
network. In the following description, numerous specific details
are set forth to provide a thorough understanding of various
embodiments. However, it will be understood by those skilled in the
art that the various embodiments may be practiced without the
specific details. In other instances, well-known methods,
procedures, components, and circuits have not been illustrated or
described in detail so as not to obscure the particular
embodiments.
[0017] In the following description and/or claims, the terms
coupled and/or connected, along with their derivatives, may be
used. In particular embodiments, connected may be used to indicate
that two or more elements are in direct physical and/or electrical
contact with each other. Coupled may mean that two or more elements
are in direct physical and/or electrical contact. However, coupled
may also mean that two or more elements may not be in direct
contact with each other, but yet may still cooperate and/or
interact with each other. For example, "coupled" may mean that two
or more elements do not contact each other but are indirectly
joined together via another element or intermediate elements.
Finally, the terms "on," "overlying," and "over" may be used in the
following description and claims. "On," "overlying," and "over" may
be used to indicate that two or more elements are in direct
physical contact with each other. However, "over" may also mean
that two or more elements are not in direct contact with each
other. For example, "over" may mean that one element is above
another element but not contact each other and may have another
element or elements in between the two elements. Furthermore, the
term "and/or" may mean "and", it may mean "or", it may mean
"exclusive-or", it may mean "one", it may mean "some, but not all",
it may mean "neither", and/or it may mean "both", although the
scope of claimed subject matter is not limited in this respect. In
the following description and/or claims, the terms "comprise" and
"include," along with their derivatives, may be used and are
intended as synonyms for each other.
[0018] Referring now to FIG. 1, a block diagram of a wireless
network illustrating a handover between two or more heterogeneous
wireless networks in accordance with one or more embodiments will
be discussed. As shown in FIG. 1, wireless network 100 may comprise
a WiMAX access network coverage area 112 disposed in and/or
proximate to a 3GPP access network coverage area 114. WiMAX access
network coverage area 112 may be serviced by a WiMAX Base Station
(WiMAX BS) 116, and likewise 3GPP access network coverage area 114
may be serviced by a 3GPP access E-UTRAN 118, e.g., a 3GPP access
network or a derivative thereof, although the scope of the claimed
subject matter is not limited in this respect.
[0019] In one or more embodiments, a user equipment/mobile station
(UE/MS) 110 may move between WiMAX access network coverage area 112
and 3GPP access network coverage area 114. If mobile station 110
moves from WiMAX coverage area 112 to 3GPP access network coverage
area 114, or if mobile station 110 movies from 3GPP access network
coverage area 114 to WiMAX coverage area 112, a handover operation
120 may occur between the WiMAX access network to the 3GPP access
network, or from the 3GPP access network to the WiMAX access
network. In one or more embodiments, handover operation 120 may
implement a handover method between WiMAX and 3GPP services where
the mobile station 110 may have one radio active at any given time.
To enable single radio operation that a single radio module of a
multi-communication platform is on at any given time, inter-radio
access technology (inter-RAT) info exchange may be utilized.
Example architectures of wireless networks capable of implementing
a handover between access services is discussed with respect to
FIG. 2.
[0020] Referring now to FIG. 2, a block diagram of an architecture
of a wireless network capable of implementing single radio handover
between another wireless network in accordance with one or more
embodiments will be discussed. In one embodiment, FIG. 2
illustrates components of an architecture for handover between a
3GPP access network and a WiMAX access network. In one or more
embodiments, a user equipment and/or mobile station 110 couples to
an evolved-UTRAN (E-UTRAN) 210 via an LTE-Uu interface which in
turn couples to serving gateway 216 via an S1-U interface. Serving
gateway 216 couples to packet data network gateway (PDN Gateway)
222 via an S5 interface, which is in turn coupled with Internet
Protocol Services (IP Services) server 226 to allow user equipment
and/or mobile station 110 to connect to the internet, although the
scope of the claimed subject matter is not limited in this
respect.
[0021] E-UTRAN 210 couples to a mobility management entity (MME)
212 via an S1-MME interface, and the serving gateway 216 couples to
the MME via an S11 interface. In some embodiments a WiMAX
Interworking Function (IWF) 214 is added to MME 212. IWF 214
implements logic to manage interworking between a WiMAX network and
a 3GPP network, e.g., a 3GPP network. MME 212 couples to a Home
Subscriber Server (HSS) 220 via an S6a interface, which in turn
coupes to an Authentication, Authorization & Accounting (AAA)
server 230.
[0022] In some embodiments WiMAX base station 116 may couple to MME
212 via an S101 interface and to WiMAX ASN-GW 218 via an R6
interface. The WiMAX ASN-GW 218 may couple to the serving gateway
216 via an S103 interface. Similarly, the WiMAX ASN-GW 218 may
couple to the PDN-GW 222 via an S2a interface. The WiMAX ASN-GW 218
may couple to the PCRF 224 and the AAA server 230.
[0023] FIG. 3 is a schematic illustration of an electronic device
300 which may be used to implement one or more network nodes in a
wireless network. By way of example, and not limitation, electronic
device 300 may be used to implement the MME 212 and/or the WiMAX
ASN-GW 218. In one embodiment, electronic device 300 may be
implemented as a computer-based system that may be coupled to one
or more networks.
[0024] Referring to FIG. 3, system 300 includes system hardware 320
and memory 330, which may be implemented as random access memory
and/or read-only memory. System hardware 320 may include one or
more processors 322, input/output ports 324, network interfaces
326, and bus structures 328. In one embodiment, processor 322 may
be embodied as an Intel.RTM. Core2 Duo.RTM. processor available
from Intel Corporation, Santa Clara, Calif., USA. As used herein,
the term "processor" means any type of computational element, such
as but not limited to, a microprocessor, a microcontroller, a
complex instruction set computing (CISC) microprocessor, a reduced
instruction set (RISC) microprocessor, a very long instruction word
(VLIW) microprocessor, or any other type of processor or processing
circuit.
[0025] In one embodiment, network interface 326 could be a wired
interface such as a wireless interface would be a general packet
radio service (GPRS) interface, a WiMAX interface, a 3G interface,
a WiFi interface, or the like. In other embodiments, the network
interface may be an Ethernet interface (see, e.g., Institute of
Electrical and Electronics Engineers/IEEE 802.3-2002) or a wireless
interface such as an IEEE 802.11a, b or g-compliant interface (see,
e.g., IEEE Standard for IT-Telecommunications and information
exchange between systems LAN/MAN--Part II: Wireless LAN Medium
Access Control (MAC) and Physical Layer (PHY) specifications
Amendment 4: Further Higher Data Rate Extension in the 2.4 GHz
Band, 802.11G-2003). Bus structures 328 connect various components
of system hardware 320. In one embodiment, bus structures 328 may
be one or more of several types of bus structure(s) including a
memory bus, a peripheral bus or external bus, and/or a local bus
using any variety of available bus architectures including, but not
limited to, 11-bit bus, Industrial Standard Architecture (ISA),
Micro-Channel Architecture (MSA), Extended ISA (EISA), Intelligent
Drive Electronics (IDE), VESA Local Bus (VLB), Peripheral Component
Interconnect (PCI), Universal Serial Bus (USB), Advanced Graphics
Port (AGP), Personal Computer Memory Card International Association
bus (PCMCIA), and Small Computer Systems Interface (SCSI).
[0026] Memory 330 may include an operating system 340 for managing
operations of electronic device 300. In one embodiment, operating
system 340 includes a hardware interface module 354 that provides
an interface to system hardware 320. In addition, operating system
340 may include a file system 350 that manages files used in the
operation of electronic device 300 and a process control subsystem
352 that manages processes executing on electronic device 300.
[0027] Operating system 340 may include (or manage) one or more
communication interfaces 344 that may operate in conjunction with
system hardware 320 to transceive data packets and/or data streams
from a remote source. Operating system 340 may further include a
system call interface module 342 that provides an interface between
the operating system 340 and one or more application modules
resident in memory 330. Operating system 340 may be embodied as a
UNIX operating system or any derivative thereof (e.g., Linux,
Solaris, etc.) or as a Windows.RTM. brand operating system, or
other operating systems.
[0028] In various embodiments, the electronic device 300 may be
coupled to a computing device 308, e.g., a personal computer, a
laptop computer, a personal digital assistant, a mobile telephone,
an entertainment device, or another computing device. Electronic
device 300 may also be coupled to one or more accompanying
input/output devices including a display 302 having a screen 304,
one or more speakers 306, a keyboard 310, one or more other I/O
device(s) 312, and a mouse 314. The other I/O device(s) 312 may
include a touch screen, a voice-activated input device, a track
ball, and any other device that allows the computing device 308 to
receive input from a user.
[0029] A file store 380 may be communicatively coupled to one or
more of the electronic device 300 or computing device 308. File
store 380 may be an internal device such as, e.g., one or more hard
drives, CD-ROM drives, DVD-ROM drives, or other types of storage
devices. File store 380 may also be external to computer 308 such
as, e.g., one or more external hard drives, network attached
storage, or a separate storage network.
[0030] Referring back to FIG. 2, in brief overview the S101
interface between the MME 212 and the WiMAX BS 116 allows for
preregistration and handover signaling to be exchanged in the
context of a handover between networks. In some embodiments a layer
2 tunnel may be established between a UE/MS 110 and the WiMAX base
station 116 and an S101 signaling interface may be implemented
through the layer 2 tunnel between the MME 212 and the WiMAX base
station 116. MIH is an example of layer-2 tunnel, while other
tunneling functions may be possible. Preregistration operations and
handover operations may be implemented at least in part via the
layer 2 tunnel. In addition, an S103 signaling interface may be
implemented between the ASN-GW 218 and the serving gateway 216. The
S103 interface may be used to forward download data.
[0031] FIG. 4 is a flow diagram illustrating operations in a method
to preregister a mobile station with a WiMAX network, according to
embodiments. Referring to FIG. 4, in some embodiments the UE/MS may
be registered in the MME 212 or in an ongoing data session with the
3GPP network. At operation 410 a decision is made to preregister
the UE/MS 110 with a WiMAX. By way of example a user of the UE/MS
may decide to preregister the UE/MS 110 with a WiMAX network.
Alternatively, logic in the UE/MS 110 may decide to couple the
UE/MS 110 to the WiMAX network.
[0032] At operation 412 a WiMAX SBC Req/Resp process is implemented
between the UE/MS 110 and the WiMAX ASN-GW 212. At operation 414
Upload/Download information is transferred from the UE/MS 110 to
the E-UTRAN 210. At operation 416 an S1 tunnel is implemented, and
at operation 418 an S101 signaling interface is implemented between
the MME 212 and the WiMAX BS 116 to enable WiMAX signaling to be
transmitted directly over the S1 tunnel.
[0033] At operation 420 an R6 MS pre-attachment procedure is
implemented between the WiMAX BS 116 and the WiMAX ASN-GW 212. At
operation 422 a WiMAX Extensible Authentication Protocol
Authentication and Key Agreement (EAP-AKA) authentication procedure
is implemented to authenticate the UE/MS with the WiMAX network. At
operation 424 a WiMAX Reg request/response process is implemented
between the UE/MS 110 and the WMAX BS 116, and at operation 426 an
MS Attachment req message is transmitted from the WiMAX BS 116 to
the WiMAX ASN-GW 212 via the R6 interface. At operation 430 a WiMAX
DSA Req/Rsp process is implemented between the UE/MS 110 and the
WiMAX BS 110, and at operation 432 a Data Path Establishment
message is transmitted between the WiMAX BS 116 and the WiMAX
ASN-GW 212 via the R6 interface.
[0034] In some embodiments the UE/MS 110 is placed into an idle
mode with the WiMAX access network after the UE/MS is preregistered
with the WiMAX access network. Thus, at operation 434 a DREG Req
operation is implemented between the UE/MS 110 and the WiMAX BS
116. In response to the request, an IM Entry State Change procedure
436 is implemented between the WiMAX BS 116 and the WiMAX ASN-GW
212 via the R6 interface. At operation 438 a data path
deregistration operation is implemented between the WiMAX BS 116
and the WiMAX ASN-GW 212 via the R6 interface.
[0035] Thus, the operations of FIG. 4 enable preregistration of the
UE/MS 110 with the WiMAX access network. In some embodiments
signaling messages between UE/MS 110 and the WiMAX BS 116 take
place, at least in part, via the S101 interface in the layer 2
tunnel established between the UE/MS 110 and the WiMAX BS 116.
Further, in some embodiments the layer 2 tunnel is maintained after
the UE/MS 110 is preregistred with the WiMAX access network. In
addition, context information associated with the UE/MS 110 may be
maintained after the mobile station has preregistered with the
WiMAX ASN-GW 212.
[0036] FIG. 5 is a flow diagram illustrating operations in a method
to implement a handover from a 3GPP access network, e.g., 3GPP
access network, to a WiMAX access network, according to some
embodiments. Referring to FIG. 5, the procedure starts with the
UE/MS 110 connected to the E-UTRAN 210. At operation 510 one or
more WiMAX power measurements collected by the UE/MS 110 are
forwarded to the E-UTRAN 210. At operation 512 a decision is made
to perform a handover from the 3GPP access network to the WiMAX
access network. The handover decision may be made by the UE/MS 110,
by the 3GPP network or another network element. In response to the
handover decision, the E-UTRAN 210 transmits a handover command to
the UE/MS 110 (operation 514). At operation 516 the WiMAX radio in
the UE/MS 110 is switched on. At operation 518 the UE/MS 110
initiates a ranging request (RNG REQ) to a base station 116. In
response to the RNG REQ the base station 116. At operation 520 the
WiMAX BS 116 transmits an IM Exit State Change Req message to the
target ASN-GW 212. In response to the IM Exit State Change Req, the
ASN-GW 212 with which the UE/MS 110 is preregistered responds with
an IM Exit State Change Rsp message 522.
[0037] At operation 524 the WiMAX BS 116 transmits a Path Reg Req
message to the WiMAX ASN-GW 212. In response to the message, the
WiMAX ASN-GW 212 generates a registration request/proxy binging
update (RRQ/PBU) message 526 which is transmitted to the home
agent/local management area, which responds with a RRP/PBA response
528. In response, the WiMAX ASN-GW 212 transmits a Path Reg Rsp
message 530 to the WiMAX BS 116, which in turn issues a RNG-RSP
message 532 to the UE/MS 110.
[0038] At operation 534 CMAC counter update procedure is
implemented between the WiMAX BS 116 and the WiMAX ASN-GW 212. At
operation 536 the WiMAX BS 116 transmits a Path Reg Ack message to
the WiMAX ASN-GW 212, and at operation 538 the WiMAX ASN-GW
transmits a Notification Request to the WiMAX BS 116 indicating
that the handover is complete, and which the WiMAX BS 116 replies
with a Notification Response 540.
[0039] At operation 542 the context information associated with the
UE/MS 110 is released. At operation 544 the MME 212 transmits a
Delete Bearer Request 544 to the serving gateway 216, which replies
with a Delete Bearer response 546. Finally, at operation 548 the
PDN-GW 222 initiates a resource deactivation procedure 548 at the
E-UTRAN 210 to release the resources associated with the 3GPP
access network.
[0040] FIG. 6 is a flow diagram illustrating operations in a method
to implement a handover from a WiMAX access network to a 3GPP
access network, according to some embodiments. The method begins
with the WiMAX radio in the UE/MS 110 on. At operation 610 a
decision is made to handover the UE/MS to the E-UTRAN 210 such that
network access is provided by the 3GPP access network. In some
embodiments the this decision may be made by the EU/MS 110, one or
more components of the WiMAX access network, or both.
[0041] At operation 612 a MOB_MIH_MSG is transmitted from the UE/MS
110 to the WiMAX BS 116 which includes an Attach Request. In
response to the MOB_MIH_MSG, the WiMAX BS 116 initiates a direct
transfer via the layer 2 tunnel that includes the S101 session ID,
the Attach Request, a descriptor of the capabilities of UE/MS 110,
and TAI.
[0042] At operations 616-620 the UE/MS 110 may be authenticated
with the 3GPP network. In some embodiments the UE/MS 110 transmits
a MOB-MIH_MSG with an authentication attachment. In response to the
MOB-MIH_MSG, the WiMAX BS 116 initiates a direct transfer via the
layer 2 tunnel that includes the S101 session ID and the
authentication request. At operation 620 an authentication process
is implemented. In some embodiments the UE/MS may be authentication
using an Authentication and Key Agreement (AKA) method, although
other techniques may be used.
[0043] At operation 622 a location update and subscriber data
retrieval process is implemented at the MME 212, and at operation
624 the MME passes a Create Session Request 624 to the serving
gateway 216. At operation 626 the serving gateway 216 forwards the
Create Session Request to the PDN-GW 222. In response to the
request, the a PCEF initiated IP CAN-Session modification procedure
162 is implemented between the PDN-GW 222 an the PCRF 224. The
PDN-GW 222 then sends a Create Session Response and a Bearer
Request 632 to the serving gateway 216, which, at operation 634,
forwards the request to the MME 212.
[0044] At operation 636 the MME 212 performs a direct transfer
through the layer 2 tunnel which includes the S101 session ID, an
Attach Accept and the Bearer Setup Request. At operation 638 the
WiMAX BS 116 forwards the Attach Accept and the Bearer Setup
Request to the UE/MS 110 via a MOB-MIH_MSG. At operation 640 the
responds via a MOB-MIH_MSG with an Attach Complete and Bearer Setup
Response. At operation 642 the WiMAX BS 116 forwards the Attach
Complete message and Bearer Setup Response to the MME via a direct
transfer through the layer 2 tunnel, and at operation 644 the MME
forwards the Create Bearer Response to the serving gateway 216. At
operation 646 the serving gateway 216 forwards the Create Bearer
Response to the PDN-GW 222.
[0045] At operation 648 the LTE radio on the UE/MS 110 is turned
on, and at operation 650 the UE/MS transmits an RRC connection
request/service request message to the MME via the WiMAX BS 116. At
operation 652 the MME 212 transmits an Initial UE Context setup
Request to the eNB 240, which establishes an RRC RB with the UE/MS
110. At operation 656 the eNB transmits an Initial UE Context Setup
Complete message to the MME 212. In response, the MME 212 transmits
a Modify Bearer request 658 to the serving gateway 216, which
provides a response at operation 660.
[0046] At operation 662 the MME 212 sends a Handover Complete
message 662 to the WiMAX BS 116. In response to the message, WiMAX
resources for the UE/MS 110 are released (operation 664) and the
WiMAX ASN-GW initiates a resource allocation deactivation procedure
to release WiMAX resources for the UE/MS 110.
[0047] Thus, the network architecture of FIG. 2 coupled with the
operations depicted in FIGS. 4-6 enables single radio handover
between a WiMAX access network and a 3GPP access network, e.g., a
3GPP network, using a layer 2 tunnel to transmit signaling
information via a S101 signaling interface.
[0048] Various aspects of the radio access network parameters may
be modified to accommodate a layer 2 capable handover. FIG. 7 is a
schematic illustration of a state machine for a 3GPP LTE mobile
station, according to embodiments. In some embodiments the 3GPP LTE
state machine model may be adapted to change between an E-UTRA RRC
Connected state and a WiMAX Active state on handover, and between
an E-UTRA RRC Idle state and a WiMAX Idle state on reselection.
Similarly, the state machine may be adapted to change between a
WiMAX Active state and a WiMAX Idle state.
[0049] In some embodiments additional capabilities parameters may
be included in the messaging between the UE/MS and the access
network. In some embodiments WiMAX parameters are inserted into the
UECapabilityInformation data structure as illustrated in FIG. 8
such that the network/eNB may be made aware that UE is capable of
perform L2 handover into WiMAX network.
[0050] In some embodiments it may be desirable to allow a
neighboring WiMAX base station to broadcast so that a mobile
station does not have to perform blind scanning, which wastes
battery power. In some embodiments, a new SIB
(SystemInformationBlockTypeWiMAX) for broadcast WiMAX mobility
related info may be introduced. Two aspects are needed for proper
measurement operations: First, a neighbor list and configurations
which informs about existing of other network. Second, a
measurement triggers/threshold which this manages mobile station
measurement behavior in a network controlled fashion. One example
of a SIB is illustrated in FIG. 9.
[0051] In some embodiments aspects of the radio resource control
(RRC) procedure may be modified to accommodate single radio
handover from a 3GPP network to a WiMAX network. Define WiMAX in
measurement configurations so that UE can obtain gap-base
measurement interval to look for nearby WiMAX network. Table I
presents a list of items which may be defined, with possible values
listed below the items:
TABLE-US-00001 TABLE I RRC Procedures Measurement objects: a list
of WiMAX neighbour BS Carrier frequency Preamble index Reporting
configurations Quantity configurations: measurement metrics and
filtering RSSI CINR others Measurement gaps: needed for
single-radio UE 5 ms WiMAX frame granularity and interleaving
pattern
[0052] A measurement report may be triggered based on
network-defined triggers or thresholds specific to WiMAX. Once a
measurement report is delivered to eNB, it enables eNB to make a
handover decision based on the report.
[0053] One embodiment of an RRC procedure is shown in FIG. 10.
Referring to FIG. 10, three signaling messages are passed between
the UE/MS 110 and the E-UTRAN 210. At operation 1010 a
ULHandoverPreparationRequest message is transmitted from the UE/MS
110 to the E-UTRAN. This is an optional signaling message which
allows MS to initiate a handover request (WiMAX profile). It is an
optional feature as WiMAX also supports fully BS controlled
handover.
[0054] At operation 1015 a HandoverFromEUTRAPreparationRequest
message is transmitted form the E-UTRAN 210 to the UE/MS 110. This
is an optional signaling message which can be either in response of
ULHandoverPreparationRequest or sent from eNB in an unsolicited
fashion. This message allows MAC context pre-update from WiMAX TB,
which is recommended for reducing interruption time. At operation
1020 a MobilityfromEUTRANcommand 1020 is transmitted from the UE/MS
110 to the E-UTRAN 201. This is a command for handover
execution.
[0055] While particular terminology is used herein to describe
various components and methods, one skilled in the art will
recognize that such terminology is intended to be descriptive and
not limiting. By way of example, the term base station is intended
to refer to a device which provides access to a network, and the
term femto access point is intended to refer to a device which
provides access to a lower-level network within the network
serviced by the base station. Similarly, the phrase "wireless
device" is intended to refer to any type of device which can
transmit or receive data on the network. It will be understood that
these phrases are intended to apply to multiple different wireless
networking standards and to networking standards and configurations
not yet described or implemented.
[0056] The terms "logic instructions" as referred to herein relates
to expressions which may be understood by one or more machines for
performing one or more logical operations. For example, logic
instructions may comprise instructions which are interpretable by a
processor compiler for executing one or more operations on one or
more data objects. However, this is merely an example of
machine-readable instructions and embodiments are not limited in
this respect.
[0057] The terms "computer readable medium" as referred to herein
relates to media capable of maintaining expressions which are
perceivable by one or more machines. For example, a computer
readable medium may comprise one or more storage devices for
storing computer readable instructions or data. Such storage
devices may comprise storage media such as, for example, optical,
magnetic or semiconductor storage media. However, this is merely an
example of a computer readable medium and embodiments are not
limited in this respect.
[0058] The term "logic" as referred to herein relates to structure
for performing one or more logical operations. For example, logic
may comprise circuitry which provides one or more output signals
based upon one or more input signals. Such circuitry may comprise a
finite state machine which receives a digital input and provides a
digital output, or circuitry which provides one or more analog
output signals in response to one or more analog input signals.
Such circuitry may be provided in an application specific
integrated circuit (ASIC) or field programmable gate array (FPGA).
Also, logic may comprise machine-readable instructions stored in a
memory in combination with processing circuitry to execute such
machine-readable instructions. However, these are merely examples
of structures which may provide logic and embodiments are not
limited in this respect.
[0059] Some of the methods described herein may be embodied as
logic instructions on a computer-readable medium. When executed on
a processor, the logic instructions cause a processor to be
programmed as a special-purpose machine that implements the
described methods. The processor, when configured by the logic
instructions to execute the methods described herein, constitutes
structure for performing the described methods. Alternatively, the
methods described herein may be reduced to logic on, e.g., a field
programmable gate array (FPGA), an application specific integrated
circuit (ASIC) or the like.
[0060] In the description and claims, the terms coupled and
connected, along with their derivatives, may be used. In particular
embodiments, connected may be used to indicate that two or more
elements are in direct physical or electrical contact with each
other. Coupled may mean that two or more elements are in direct
physical or electrical contact. However, coupled may also mean that
two or more elements may not be in direct contact with each other,
but yet may still cooperate or interact with each other.
[0061] Reference in the specification to "one embodiment" or "an
embodiment" means that a particular feature, structure, or
characteristic described in connection with the embodiment is
included in at least an implementation. The appearances of the
phrase "in one embodiment" in various places in the specification
may or may not be all referring to the same embodiment.
[0062] Although embodiments have been described in language
specific to structural features and/or methodological acts, it is
to be understood that claimed subject matter may not be limited to
the specific features or acts described. Rather, the specific
features and acts are disclosed as sample forms of implementing the
claimed subject matter.
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