EXHIBIT 3

Case 2:23-cv-00444-JRG Document 1-4 Filed 09/27/23 Page 1 of 17 PageID #: 65
(12) United States Patent 

Akgun et al. 

US00713.0625B2 

US 7,130,625 B2 

Oct. 31, 2006 

(10) Patent No.: 

(45) Date of Patent: 

(54) SYSTEM AND METHOD FOR A UNIVERSAL 

WIRELESS ACCESS GATEWAY 

(75) Inventors: Ali Akgun, Chicago, IL (US); Michael 

Borella, Naperville, IL (US) 

(73) Assignee: 3Com Corporation, Marlborough, MA 

(US) 

(*) Notice: Subject to any disclaimer, the term of this 

patent is extended or adjusted under 35 

U.S.C. 154(b) by 722 days. 

(21) Appl. No.: 10/186,957 

(22) Filed: Jul. 1, 2002 

(65) Prior Publication Data 

US 2004/OO29585 A1 Feb. 12, 2004 

(51) Int. Cl. 

H04O 7/20 (2006.01) 

(52) U.S. Cl. ................... 455/422.1; 455/466:455/439; 

455/450; 455/445 

(58) Field of Classification Search ............. 455/422.1, 

455/450, 466 

See application file for complete search history. 

(56) References Cited 

U.S. PATENT DOCUMENTS 

6,374,112 B1 4/2002 Widegren et al. ........... 455,452 

OTHER PUBLICATIONS 

CommWorks a 3Com Company, "3 G Data System For cdma2000 

Wireless Networks', 2001. 

IEEE Std 802 11a-1999, “Part 11: Wireless LAN Medium Access 

Control (MAC) and Physical Layer (PHY) Specifications—High 

Speed Physical Layer in the 5 GHZ Band", IEEE Computer Society. 

1999. 

IEEE Std 802.11b-1999, “Part 11: Wireless LAN Medium Access 

Control (MAC) and Physical Layer (PHY) Specifications: Higher 

Speed Physical Layer Extension in the 2.4 GHz Band", IEEE 

Computer Society, Sep. 16, 1999. 

1. 

IEEE Std 802.1X-2001, “IEEE Standard For Local Metropolitan 

Area Networks—Port-Based Network Access Control', IEEE Com 

puter Society, Jun. 14, 2001. 

IEEE Std 802.3, 2000 Edition, “Part 3: Carrier Sense Multiple 

Access With Collision Detection (CSMA/CD) Access Methods and 

Physical Layer Specifications”, IEEE Computer Society 2000. 

IEEE Std 802.11, “Information Technology-Telecommunications 

and Information Exchange Between Systems—Local and Metro 

politan Area Networks Specific Requirements', 1999 edition. 

Congdon, et al. “IEEE 802.1X Radius Usage Guidelines'; Internet 

Engineering Task Force (IETF), Internet-Draft <draft-congdon 

radius-8021x20.txt, Jun. 17, 2002. 

Internet Engineering Task Force (IETF), Requests For Comments 

(RFC) 1661, “The Point-To-Point Protocol (PPP), Jul 1994. 

(Continued) 

Primary Examiner Lester G. Kincaid 

Assistant Examiner Fred A. Casca 

(74) Attorney, Agent, or Firm McDonnell Boehnen 

Hulbert & Berghoff LLP 

(57) ABSTRACT 

The present embodiments provide a system and method for 

seamlessly roaming between different wireless access tech 

nologies. In an exemplary embodiment, a universal wireless 

access gateway (UWAG) may include a shared component 

and a first environment access module (EAM) that commu 

nicates with the shared component to enable access to a first 

network using a first wireless access technology. Addition 

ally, the UWAG may include a second EAM that commu 

nicates with the shared component. The second EAM and 

shared component may enable access to a second network 

using a second wireless access technology that differs from 

the first wireless access technology. An exemplary data 

structure including various pointer blocks and data blocks 

may also be provided for switching between different wire 

less access technologies. 

31 Claims, 6 Drawing Sheets 

Universal 

wireless 

access 

Authentication Server 

90 

 

 

 

Case 2:23-cv-00444-JRG Document 1-4 Filed 09/27/23 Page 2 of 17 PageID #: 66
US 7,130,625 B2 

Page 2 

OTHER PUBLICATIONS 

Internet Engineering Task Force (IETF), Requests For Comments 

(RFC) 1662, “PPP In HDLC-Like Framing”, Jul 1994. 

Internet Engineering Task Force (IETF), Requests For Comments 

(RFC) 2002, “IP Mobility Support”, Oct. 1996. 

Internet Engineering Task Force (IETF), Requests For Comments 

(RFC) 2003, “IP Encapsulation Within IP”, Oct. 1996. 

Internet Engineering Task Force (IETF), Requests For Comments 

(RFC) 2004, “Minimal Encapsulation Within IP', Oct. 1996. 

Internet Engineering Task Force (IETF), Requests For Comments 

(RFC) 2005. “Applicability Statement For IP Mobility Support', 

Oct. 1996. 

Internet Engineering Task Force (IETF), Requests For Comments 

(RFC) 2006. “The Definition of Managed Objects for IP Mobility 

Support Using SMIv2, Oct. 1996. 

Internet Engineering Task Force (IETF), Requests For Comments 

(RFC) 2138. “Remote Authentication Dial In User Service 

(RADIUS)”, Apr. 1997. 

Internet Engineering Task Force (IETF), Requests For Comments 

(RFC) 2139, “RADIUS Accounting”, Apr. 1997. 

Internet Engineering Task Force (IETF), Requests For Comments 

(RFC) 2284, “PPP Extensible Authentication Protocol (EAP), Mar. 

1998. 

Internet Engineering Task Force (IETF), Requests For Comments 

(RFC) 2516, “A Method For Transmitting PPP Over Ethernet 

(PPPoE)”. Feb. 1999. 

Internet Engineering Task Force (IETF), Requests For Comments 

(RFC) 2865. “Remote Authentication Dial In User Service 

(RADIUS)”, Jun. 2000. 

Internet Engineering Task Force (IETF), Requests For Comments 

(RFC) 2866, “RADIUS Accounting”, Jun. 2000. 

Internet Engineering Task Force (IETF), Requests For Comments 

(RFC) 2867, “RADIUS Accounting Modification For Tunnel Pro 

tocol Support”. Jun. 2000. 

DRAFT Supplement to STANDARD for Information Technol 

ogy-Telecommunications and information exchange between sys 

tems-Local and metropolitan area networks-Specific requirements 

Part 11: Wireless LAN Medium Access Control (MAC) and Physi cal Layer (PHY) specifications: Further Higher-Speed Physical 

Layer Extension in the 2.4 GhzBand, IEEStd 802.11g/D6.1, Jan. 

2003 (Supplement to ANSI/IEEE Std 802.11 1999(Reaf 2003)), pp. 

1-58. 

PCT International Search Report for 3Com Corporation et al., in 

PCT/US03/20529, dated Jun. 30, 2003. 

Case 2:23-cv-00444-JRG Document 1-4 Filed 09/27/23 Page 3 of 17 PageID #: 67
U.S. Patent Oct. 31, 2006 Sheet 1 of 6 US 7,130,625 B2 

10 

Packet 

control 

function 

Base station 

system Universal 

wireless 

aCCeSS 

gateway 

60 

Authentication 

Server 

90 

 

 

 

 

 

 

 

 

 

Case 2:23-cv-00444-JRG Document 1-4 Filed 09/27/23 Page 4 of 17 PageID #: 68
U.S. Patent Oct. 31, 2006 Sheet 2 of 6 

Shared Component 

210 

Mobile IP foreign agent 

PPP termination 

RADIUS and/or Diameter client 

Routing 

RIP, OSPF, IS-S and BGP 

ingress filtering 

Tunneling 

IPsec 

NAT 

FireWall 

Legal wiretap (CALEA) 

QOS 

SNMP server and generic MIBs 

US 7,130,625 B2 

PDSN EAM 802.11 EAM 

220 230 

RP (A10A1) interface MobileRG interface 

P-P interface RG MBS 

PDSN MBS 

FIG. 2 

GGSN EAM 

240 

GTP-u interface 

GTP-C interface 

GTP' interface 

GGSN MBS 

Case 2:23-cv-00444-JRG Document 1-4 Filed 09/27/23 Page 5 of 17 PageID #: 69
U.S. Patent Oct. 31, 2006 Sheet 3 of 6 US 7,130,625 B2 

Second Context Data Block (e.g., Trans. Cont) 

340 

Data Structure 

300 Connection State EAM 

Data Block 

EAM Type 344 

Pointer co Accounting Info Data 

User 1 Pointer User Profile Block 

User 2 Pointer 346 

Data Pointer User Profile 

Block 342 Data Block 

348 

Active Users List 310 

Transition Context Pointer First Context Data Block (e.g., Active Context) 

330 

Active Context Pointer 

Management Connection State EAM 

Pointer Block 320 Data Block 

EAM Type 334 

EAM Pointer 

Accounting 

Info Data 

Block 

336 

Accounting lnfo 

Pointer 

User Profile 

Pointer 

Dafa Pointer User Profile 

Block 332 Data Block 

338 

FIG. 3 

 

Case 2:23-cv-00444-JRG Document 1-4 Filed 09/27/23 Page 6 of 17 PageID #: 70
U.S. Patent Oct. 31, 2006 Sheet 4 of 6 US 7,130,625 B2 

Second Context Data Block (e.g., Trans. Cont) 

440 

Data Structure 

400 Connection State EAM - Data Block 

EAM Type 444 

EAM Pointer 

Accounting info 

Pointer 

User Profile 

Pointer 

User Profile 

Data Pointer Data Block Active Users List 410 Block 442 448 

Accounting 

Info Data 

Block 

450 

Transition Context Pointer First Context Data Block (e.g., Active Context) 

Active Context Pointer 430 

Management Connection State EAM 

Pointer Block 420 EAM Type Data Block 

434 

Accounting info 

Pointer 

User Profile 

Pointer 

EAM Pointer 

User Profile 

Data Pointer Data Block 

Block 432 4.38 

FIG. 4 

 

Case 2:23-cv-00444-JRG Document 1-4 Filed 09/27/23 Page 7 of 17 PageID #: 71
U.S. Patent Oct. 31, 2006 Sheet 5 of 6 US 7,130,625 B2 

Transition Context Pointer 

Active Context Pointer 

Management 

Pointer Block 320 First 

Context 

Data Block 

330 

FIG. 5a 

Second 

Context 

Data Block 

Transition Context Pointer 340 

Active Context Pointer 

Management 

Pointer Block 320 First 

Context 

Data Block 

330 

FIG. 5b. 

 

Case 2:23-cv-00444-JRG Document 1-4 Filed 09/27/23 Page 8 of 17 PageID #: 72
U.S. Patent Oct. 31, 2006 Sheet 6 of 6 US 7,130,625 B2 

Second 

Context 

Data Block 

34 Transition Context Pointer 340 

Active Context Pointer 

Management First 

Pointer Block 320 Context 

Data Block 

330 

FIG. 5C 

Second 

Context 

Data Block 

Transition Context Pointer 340 

Active Context Pointer 

Management 

Pointer Block 320 

FIG. 5d 

 

 

Case 2:23-cv-00444-JRG Document 1-4 Filed 09/27/23 Page 9 of 17 PageID #: 73
US 7,130,625 B2 

1. 

SYSTEMAND METHOD FOR A UNIVERSAL 

WRELESS ACCESS GATEWAY 

FIELD OF INVENTION 

This invention relates to wireless telecommunications 

networks. More specifically, it relates to a system and 

method for switching between multiple wireless access 

technologies in a universal wireless access gateway. 

BACKGROUND OF INVENTION 

Wireless technology has become an important part of 

modern communications. From cellular phones to personal digital assistants, wireless technology enables devices to 

communicate with networks and other devices while in a 

mobile setting. Additionally, as wireless networks continue 

to grow and mobile devices continue to become more 

popular, it is expected that the importance and utility of 

wireless technology will increase as well. 

A number of access technologies have been established 

for wireless communications, such as Code-Division Mul 

tiple Access (CDMA), Global System for Mobile Commu 

nications (GSM), Institute for Electrical and Electronics 

Engineers (IEEE) 802.11, Time-Division Multiple Access 

(TDMA), and so forth. Unfortunately, present wireless net 

works typically do not allow for mobile devices to commu 

nicate using multiple wireless access technologies. This 

limitation may severely restrict the utility of a mobile 

device, and prevent the mobile device from operating when 

a network that employs a given wireless access technology 

is not available. 

Accordingly, it is desirable to have a system and method 

for wireless communications that overcomes the above 

deficiencies associated with the prior art. This may be 

achieved by using a universal wireless access gateway to 

allow for Switching of wireless access technologies 

employed by a mobile node. 

SUMMARY 

The present embodiments provide a system and method 

for seamlessly roaming between different wireless access 

technologies. An exemplary method may include providing 

a universal wireless access gateway with a shared compo 

nent and a first environment access module to establish a 

first wireless connection with a first network. Additionally, 

the method may include communicating with the first net 

work along the first wireless connection using a first wireless 

access technology. Furthermore, the method may also 

include providing the universal wireless access gateway 

with a second environment access module. Additionally, the 

method may include establishing a second wireless connec 

tion between the universal wireless access gateway and a 

second network using the shared component and the second 

environment access module. The exemplary method may 

also include communicating with the second network along 

the second wireless connection using a second wireless 

access technology that differs from the first wireless access 

technology. 

The present application also provides an exemplary uni 

versal wireless access gateway. The universal wireless 

access gateway may include a shared component and a first 

environment access module that communicates with the 

shared component to enable access to a first network using 

a first wireless access technology. Furthermore, the universal 

wireless access gateway may also include a second envi 

10 

15 

25 

30 

35 

40 

45 

50 

55 

60 

65 

2 

ronment access module that communicates with the shared 

component to enable access to a second network using a 

second wireless access technology that differs from the first 

wireless access technology. 

Additionally, the present application provides another 

exemplary method for seamlessly roaming between different 

wireless access technologies within a universal wireless 

access gateway. The exemplary method may include linking 

an active context pointer to a first context data block storing 

data associated with a first wireless access technology. 

Furthermore, the method may include communicating with 

a first network using the first wireless access technology. 

The method may also include receiving data associated with 

a second wireless access technology from a second network. 

Also, the method may include storing the data associated 

with the second wireless access technology within a second 

context data block and linking a transition context pointer to 

the second context data block. Furthermore, the method may 

also include Switching the active context pointer and the 

transition context pointer and communicating with the sec 

ond network using the second wireless access technology. 

In another exemplary embodiment described in the 

present application, a universal wireless access gateway may 

have a memory for storing data for access by an application 

program that is executed on a data processing system. The 

memory may store a data structure that includes information 

resident in a database used by the application program. 

Additionally, the data structure may include a management 

pointer block having an active context pointer and a transi 

tion context pointer. Also, the data structure may have a first 

context data block storing a first data pointer block that links 

to a first environment access module data block. Addition 

ally, the active context pointer may link to the first context 

data block. The data structure may also include a second 

context data block storing a second data pointer block that 

links to a second environment access module data block, and 

the transition context pointer may link to the second context 

data block. 

Another exemplary method described in the present appli 

cation may include linking an active context pointer to a first 

context data block associated with a first wireless access 

technology. Additionally, the method may include providing 

the universal wireless access gateway with a shared com 

ponent and a first environment access module to establish a 

first wireless connection with a first network. Furthermore, 

the method may include communicating with the first net 

work along the first wireless connection using the first 

wireless access technology. Also, the method may also 

include providing the universal wireless access gateway 

with a second environment access module that is linked to 

the shared component. Additionally, the method may include 

linking a transition context pointer to a second context data 

block corresponding to a second wireless access technology 

that differs from the first wireless access technology. Fur 

thermore, the method may also include Switching the active 

context pointer and the transition context pointer. Also, the 

method may include establishing a second wireless connec 

tion between the universal wireless access gateway and a 

second network using the shared component and the second 

environment access module. The method may also include 

communicating with the second network along the second 

wireless connection using the second wireless access tech 

nology. 

Case 2:23-cv-00444-JRG Document 1-4 Filed 09/27/23 Page 10 of 17 PageID #: 74
US 7,130,625 B2 

3 

BRIEF DESCRIPTION OF DRAWINGS 

FIG. 1 shows a block diagram of an exemplary wireless 

telecommunications network; 

FIG. 2 shows a functional block diagram of an exemplary 

universal wireless access gateway (UWAG) for use in the 

wireless telecommunications network of FIG. 1; 

FIG. 3 shows a block diagram of an exemplary data 

structure for use with the UWAG of FIG. 2; 

FIG. 4 shows a block diagram of another exemplary data 

structure for use with the UWAG of FIG. 2; and 

FIGS. 5a-d show exemplary data structures illustrating 

Switching between different wireless access technologies 

within the UWAG of FIG. 2. 

DETAILED DESCRIPTION 

I. Exemplary Wireless Telecommunications Network 

In an exemplary embodiment, a wireless telecommunica 

tions network may include a universal wireless access 

gateway (UWAG) that enables a mobile node to roam 

seamlessly between networks that use different wireless 

access technologies. In an exemplary scenario, the UWAG 

may have a shared component that includes generic func 

tionality common to a number of different wireless access 

technologies. Additionally, the UWAG may also include 

environment access modules (EAMs) that include function 

ality that is specific to the type of wireless access technology 

being used. To illustrate, an exemplary UWAG may have a 

CDMA EAM that has functionality specific to CDMA. 

Thus, the EAMs may serve as pluggable modules to the 

generic functions within the shared component. 

Turning now to the drawings, FIG. 1 illustrates an exem 

plary wireless telecommunications network 10, where a 

mobile node 12 may communicate with a network 70 via a 

UWAG 60. Additionally, the network 70 may communicate 

with a home agent 80, and the mobile node 12 may com 

municate with an authentication server 90 via the UWAG 60. 

Other intermediate components shown in FIG. 1 will be 

described in more detail shortly. It should be understood that 

the wireless telecommunications network 10 may alterna 

tively include more or fewer components, such as additional 

UWAGs or authentication servers. 

A. Exemplary Mobile Node 

In the present embodiment, the mobile node 12 may be 

any type of wireless device. Such as a cellular phone, laptop 

computer, portable-facsimile device, personal digital assis 

tant (PDA), and/or two-way pager. Additionally, the mobile 

node 12 may include a variety of different wireless trans 

ceivers for sending and receiving data using any number of 

different wireless access technologies. For example, in the 

present embodiment, the mobile node 12 may communicate 

with the UWAG 60 via access technologies such as Code 

Division Multiple Access 2000 (CDMA2000), IEEE 802.11, 

Global Packet Radio Service (GPRS), and/or Universal 

Mobile Telecommunications System (UMTS), all of which 

will be described in more detail later. Additionally, it should 

be understood that in alternate embodiments, the mobile 

node 12 may employ other types of wireless access tech 

nologies within the wireless telecommunications network 

10. For example, the mobile node 12 may alternatively use 

technologies such as Time-Division Multiple Access 

(TDMA), or Frequency Division Multiple Access (FDMA) 

for wirelessly sending and receiving data. Additionally, it 

should be noted that although only a single roaming mobile 

node 12 is depicted in FIG. 1, any number of mobile nodes 

10 

15 

25 

30 

35 

40 

45 

50 

55 

60 

65 

4 

may alternatively communicate with the UWAG 60 within 

the wireless telecommunications network 10. 

B. Exemplary Network 

Although the network 70 is depicted as a single entity in 

FIG. 1, it should be understood that a wide variety of 

network types may be included within the network 70. For 

example, the network 70 may include a CDMA2000 net 

work, an IEEE 802.11 network, and/or a GPRS/UMTS 

network, all of which may or may not be in communication 

with one another. Furthermore, the network 70 may include 

a combination of network types. For example, in an alternate 

embodiment, the network 70 may include a combination of 

an IEEE 802.11 local area network (LAN) and a wireline 

IEEE 802.3 Ethernet network. 

C. Exemplary Home Agent 

The home agent 80 may be a registration server that the 

mobile node 12 may remotely access in order to communi 

cate with the network 70. Additionally, the home agent 80 

may communicate with the UWAG 60, and include a tim 

eout mechanism (not shown) in order to timeout a connec 

tion to the UWAG 60 if it is not responsive. In the present 

embodiment, the home agent 80 may be installed at a central 

office (CO) of a telephone company. Further, the home agent 

80 may be capable of connecting and disconnecting thou 

sands of user sessions from various mobile nodes. An 

exemplary home agent 80 for use in the present embodiment 

may be the Total Control Enterprise Network Hub incorpo rating an integral general purpose computing platform, e.g., 

the HiPerarcTM card, both of which are commercially avail 

able from the present assignee, 3COM Corporation. This 

computing platform card may allow the home agent 80 to 

run a commercially available stand-alone operating system, 

Such as a custom operating system designed for the exem 

plary wireless telecommunications network 10. 

Additionally, the home agent 80 may utilize other remote 

access software products, such as RADIUS (Remote 

Authentication Dial In User Service) or DIAMETER soft 

ware. These protocols may be utilized during communica 

tion with the authentication server 90. Further, previously 

described connection mechanisms may also utilize the 

RADIUS protocol, which is described in Internet Engineer 

ing Task Force (IETF) Request for Comments (RFC) 2865, 

“Remote Authentication Dial In User Service (RADIUS), the contents of which are specifically incorporated in its 

entirety herein by reference. It should be understood that a 

number of other commercially available or known home 

agents and connection protocols may also be utilized with 

the present embodiment. 

D. Exemplary Authentication Server 

The authentication server 90 may be any type of server or 

computing device that performs authentication and access 

authorization for the mobile node 12 when connecting to the 

network 70. Consistent with the RADIUS protocol, the 

authentication server 90 may receive an access-request 

packet from the UWAG 60 on behalf of the mobile node 12, 

and the authentication server 90 may respond with an 

access-accept packet or an access-reject packet (packets not 

shown). The format of access-request packets, access-reject 

packets, and access-accept packets is described within RFC 

2865. 

The mobile node 12 may be authenticated through a 

variety of different mechanisms. For example, the mobile 

node 12 may authenticate itself using a username/password 

scheme with the authentication server 90. If the authentica 

tion server 90 determines that the username and password 

Case 2:23-cv-00444-JRG Document 1-4 Filed 09/27/23 Page 11 of 17 PageID #: 75
US 7,130,625 B2 

5 

are not valid, the requested connection may be rejected with 

an access-reject packet. Alternatively, if the username and 

password are valid, the authentication server 90 may enable 

the mobile node 12 with an access-accept packet to access 

the network 70 via the UWAG 60. If the authentication 

server 90 is unavailable or unable to process the username 

and password that it has received, it may ask the UWAG 60 

to try a connection with another authentication server. 

II. Exemplary Communication Using Different Wireless 

Access Technologies 

In the present embodiment, the mobile node 12 depicted 

in FIG. 1 may communicate using CDMA2000, IEEE 

802.11, GPRS, and/or UMTS, though other wireless access 

technologies may alternatively be utilized. For more infor 

mation on any of these access technologies, one can refer to 

U.S. patent application Ser. No. 10/186,810, (MBHB Case 

No. 02-048-A), entitled “System and Method for Roaming 

Between Wireless Networks, filed Jul. 1, 2002, the contents 

of which are specifically incorporated in its entirety herein 

by reference. 

A. Exemplary CDMA Communication 

CDMA is a wireless communication system for a popular digital, spread spectrum, cellular phone service. The CDMA 

protocol family includes not only CDMA, but also camaCne 

and CDMA2000. Unless otherwise stated to the contrary, for 

purposes of the present application, a reference to CDMA 

includes the cdmaOne and CDMA2000 wireless communi 

cation technologies (including all of their standard commu 

nication protocols), as well as any future wireless commu 

nication technologies based on CDMA2000. One can refer 

to the CDMA standards (e.g., TIA/EIA IS-2000 series) published by the Telecommunications Industry Association 

(TIA) for more information on CDMA technology, commu 

nication protocols, and components. It should also be under 

stood that unless stated to the contrary, standard CDMA 

components are used with the present embodiments. 

CDMA includes a suite of airlink, radio network, and 

Internet Protocol (IP) standards that allow IP network access 

by cellular devices (i.e., mobile nodes). In the present 

embodiment, the mobile node 12 may gain network access 

by negotiating with a base station system 14 for an airlink 

channel. The base station system 14 may include an antenna, 

Such as a radio tower, for sending and/or receiving the 

CDMA signals, though other transmission mechanisms may alternatively be utilized. Additionally, it should be under 

stood that the base station system 14 may include other 

standard CDMA components, such as a base station con 

troller (BSC) and/or a mobile switching center (MSC). 

Once an airlink channel is allocated, a BSC within the 

base station system 14 may use an interface. Such as an 

A8/A9 interface, to set up a packet data session with an 

interface node 20 (e.g., packet control function (PCF)). The 

interface node 20 may be implemented in software, hard 

ware, or a combination of both. Additionally, or alterna 

tively, the interface node 20 may be part of the UWAG 60 

or the base station system 14. 

Furthermore, the interface node 20 may use another 

interface, such as an A10/A11 or radio access network 

(RAN) packet data serving node (PDSN) interface (R-P 

interface), to set up a packet data session with the UWAG 

60. As will be described later, the UWAG 60 may include 

functionality for a PDSN that can be used for processing 

CDMA data. 

In the present embodiment, the mobile node 12 can then 

initiate a Point-to-Point Protocol (PPP) session that is ter 

minated at the UWAG 60. IP traffic can be carried over the 

10 

15 

25 

30 

35 

40 

45 

50 

55 

60 

65 

6 

PPP session and transferred between the mobile node 12 and 

the UWAG 60. The UWAG 60 may also responsible for 

relaying IP traffic to the network 70, which may include an 

IP network such as the Internet. For more information on 

PPP, one can refer to RFC 1661, the contents of which are 

specifically incorporated in its entirety herein by reference. 

B. Exemplary 802.11 Communication 

IEEE 802.11 is a popular wireless access technology that 

allows Ethernet-like media framing over the 2.4 GHz wire 

less spectrum. Like wireline Ethernet (also referred to herein 

as IEEE 802.3 or simply 802.3), there is no admission 

control and carrier sense multiple access (CSMA) is used. 

However, where IEEE 802.3 uses collision detection, IEEE 

802.11 (also referred to herein as wireless Ethernet or simply 

802.11), uses collision avoidance, such as by including in 

every frame sent the duration of the frame in units of time. 

Once an 802.11 station sends a frame, other 802.11 stations 

may avoid transmitting until the time duration specified 

within the frame has expired. 

Furthermore, 802.11 packets may use the same format as 

802.3 packets and can thus be passed from a wireless 

Ethernet to wireline Ethernet setting via an 802.11 access 

point, such as the 802.11 access point 30 shown in FIG. 1. 

In the present embodiment, the 802.11 access point 30 may 

forward data received from the mobile node 12 to the 

UWAG 60. Furthermore, as will be described later, the 

UWAG 60 may include functionality typically performed by 

an 802.11 roaming gateway, which generally receives and 

processes 802.11 data. For more information on wireless 

Ethernet, one can refer to the Institute for Electrical and 

Electronics Engineers (IEEE) standards 802.11a, 802.11b. 

and 802.11g, the contents of which are specifically incor 

porated in their entirety herein by reference. 

Authentication in 802.11 networks may be performed in 

a number of ways. Relatively simple mechanisms based on 

user identification/password pairs can be used for authenti 

cating a mobile node. Additionally, 802.11 networks may 

employ 802.1X, which is a port-based authentication proto 

col for IEEE 802 networks. 802.11x allows a client (e.g., mobile node 12), access point (e.g., 802.11 access point 30), 

and authentication server (e.g., authentication server 90) to 

work together to authenticate the client for network access. 

802.1X typically uses an extensible authentication protocol 

(EAP) to exchange authentication information. EAP allows 

the use of varied authentication mechanisms and parameters, Such as one-time passwords, Kerberos, Transparent LAN 

service (TLS), and other mechanisms. For more information 

on EAP, one can refer to RFC 2284, the contents of which 

are specifically incorporated in its entirety herein by refer CCC. 

C. Exemplary GSM Communication 

Another wireless access technology that may be used in 

the exemplary wireless telecommunications network 10 is 

Global System for Mobile Communications (GSM), which 

typically uses narrowband TDMA signals for wirelessly 

transmitting data. The GSM protocol family includes not 

only GSM, but also General Packet Radio Service (GPRS) 

and Universal Mobile Telecommunications System 

(UMTS). Unless otherwise stated to the contrary, for pur 

poses of the present application, a reference to GSM 

includes GPRS/UMTS (including all of their standard com 

munication protocols), as well as any future wireless com 

munication technologies based on GPRS/UMTS. Addition 

ally, other GSM standards, such as Enhanced Data Rates for 

GSM Evolution (EDGE), and third generation GSM ser 

vices (3GSM), may also be used with the present embodi 

Case 2:23-cv-00444-JRG Document 1-4 Filed 09/27/23 Page 12 of 17 PageID #: 76
US 7,130,625 B2 

7 

ments. For more information on GSM technology, commu 

nication protocols, and components, one can refer to the 

GSM standards published by the European Telecommuni 

cations Standards Institute (ETSI). Despite their technological differences, GSM and CDMA 

can operate in a similar fashion. Instead of a PDSN and a 

PCF, GSM can use a Gateway GPRS Support Node (GGSN) 

and a Serving GPRS Support Node (SGSN), respectively. 

Also, rather than an R-P interface, GSM can use a GPRS 

Tunneling Protocol (GTP) interface. Thus, as shown in FIG. 

1, the mobile node 12 may communicate with the UWAG 60 

via an interface node 40, which may be an SGSN. Addi 

tionally, as will be described later, the UWAG 60 may include functionality typically performed by a GGSN. It 

should be understood that unless stated to the contrary, standard GSM components are used with the present 

embodiments, and that GSM technology and its components 

may be readily substituted for CDMA technology and its 

components in connection with the present embodiments. 

D. Exemplary Handoffs Between Different Wireless Access 

Technologies 

In the present embodiment, a handoff may occur when the 

mobile node 12 switches to a different wireless access 

technology or switches to a different UWAG from the one it 

is currently using. Two types of handoffs that may be 

performed within the exemplary wireless telecommunica 

tions network 10 are intra-UWAG handoffs and inter 

UWAG handoffs. In an intra-UWAG handoff, the UWAG 

with which a mobile node communicates may remain the 

same, but the mobile node may roam to a network that 

employs a different wireless access technology. To illustrate, 

an intra-UWAG handoff may occur if the mobile node 12 

originally communicates with the UWAG 60 using CDMA 

(e.g., via the base station system 14 and interface node 20), 

but then Switches and begins using wireless Ethernet (e.g., 

via the 802.11 access point 30). In such a scenario, the 

UWAG 60 may have to dynamically change the type of 

framing that is used by the mobile node 12. 

In an inter-UWAG handoff, a mobile node 12 may cease 

communication with a UWAG and roam to a new UWAG. 

In Such a scenario, a hard handoff may occur, which implies 

that the connection to the old UWAG may be broken before 

a connection to the new UWAG is made. Additionally, the 

hard handoff may be followed by a Mobile IP handoff, which 

implies the mobile node accesses a new foreign agent within 

the new UWAG as opposed to the old foreign agent within 

the old UWAG. 

Alternatively, in an inter-UWAG handoff situation, the 

wireless network 10 may employ a deferred handoff. During 

a deferred handoff, a mobile node may remain in commu 

nication with the serving (old) UWAG while traffic is 

tunneled via the new UWAG to and from the mobile node. 

When the mobile node's user session goes dormant or is idle 

for a period of time, the new UWAG may complete the 

deferred handoff by terminating the tunnel to the old UWAG 

and sending a Mobile IP agent advertisement to the mobile 

node so that it will be triggered to perform a Mobile IP 

handoff to a new foreign agent within the new UWAG. 

III. Exemplary Environment Access Module 

Turning now to FIG. 2, a block diagram illustrating 

exemplary functional components within the UWAG 60 is 

shown. In the present embodiment, the UWAG 60 may include a shared component 210, and a number of protocol 

specific EAMs, such as a PDSN EAM 220, an 802.11 EAM 

230, and a GGSN EAM 240. The shared component 210 

may include functionality that is common to a number of 

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different wireless access technologies. The protocol-specific 

EAMs may include functionality that is specific to a respec 

tive wireless access technology (e.g., the 802.11 EAM may 

include functionality specific to the 802.11 access technol 

ogy). 

Additionally, although not shown in FIG. 2, it should be 

understood that the UWAG 60 may include a storage unit 

that uses any known storage mechanism, Such as a magnetic 

or optical hard disk drive, buffer, or memory unit (e.g., 

random access memory (RAM), read-only memory (ROM), 

programmable ROM (PROM), erasable PROM (EPROM), 

electrically erasable PROM (EEPROM)). As will be 

described later, various data structures used for storing data 

pertaining to the mobile node 12 may be kept within the 

storage unit of the UWAG 60. Furthermore, the UWAG 60 

may also include a central processing unit (CPU) for pro 

cessing data received from the mobile node 12 and/or other 

components within the wireless network 10. 

A. Exemplary Shared Component 

The shared component 210 may include functionality that 

is common to any number of different wireless access 

technologies, such as CDMA, 802.11, and GSM. For 

example, the present shared gateway 210 may support 

Mobile IP and thus include a foreign agent that communi 

cates with the home agent 80. Additionally, the shared 

component 210 may support various framing and encapsu 

lating protocols, such as the point-to-point protocol (PPP). 

The shared component 210 may also include various Secu 

rity functionality, such as Internet Protocol Security (IPsec), 

firewalls, and ingress filtering, all of which may prevent 

unauthorized clients from accessing the network 70. 

Various authentication mechanisms, such as RADIUS and 

Diameter, may also be included within the shared compo 

nent 210. The shared component 210 may also have a 

number of different addressing and routing mechanisms, 

such as the Routing Information Protocol (RIP), Open 

Shortest Path First (OSPF) routing protocol, Intermediate 

System to Intermediate System (IS IS) routing protocol 

and Border Gateway Protocol (BGP). Furthermore, the 

shared component 210 may also support other miscellaneous 

functionality, such as Simple Network Management Proto 

col (SNMP) servers and generic Management Information 

Bases (MIBs), legal wiretapping under the Communications 

Assistance for Law Enforcement Act (CALEA), network 

address translation (NAT), and Quality of Service (QoS). It 

should be understood that the functionality described here is 

merely exemplary, and that the shared component 210 may 

alternatively include different functionality than specified 

here. Additionally, it should be understood that any func 

tionality within the shared component 210 may be imple 

mented in hardware, software, or a combination of both. 

B. Exemplary Protocol-Specific EAMs 

As shown in FIG. 2, the UWAG 60 may also include any 

number of different protocol-specific EAMs. These EAMs 

may serve as pluggable modules to the shared component 

210 via various application program interfaces (APIs). Addi 

tionally, these EAMs may enable the mobile node 12 to 

roam and communicate with networks using different wire 

less access technologies. 

The PDSN EAM 220 may have a number of functions that 

are specific to PDSNs. Hence, the UWAG 60 may perform 

the functionality of a PDSN as used in a CDMA network. In 

particular, the PDSN EAM 220 may enable the UWAG 60 

to support R-P (A10/A11) interfaces, and PDSN to PDSN 

(P-P) interfaces. Furthermore, the PDSN EAM 220 may 

enable the UWAG 60 to store PDSN MIBs, which may 

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US 7,130,625 B2 

include a variety of different types of data. In particular the 

PDSN MIBs may include management information that a 

network service provider administering the network 70 may 

wish to collect about the PDSN EAM 220. 

The 802.11 EAM 230 may perform functionality specific 

to an 802.11 roaming gateway. For example, the 802.11 

EAM 230 may support various mobile node to gateway 

interfaces, which may be based on Mobile IP, RADIUS 

and/or Diameter protocols. Additionally, the 802.11 EAM 

230 may also include roaming gateway MIBs usually 

present within 802.11 roaming gateways. 

The GGSN EAM 240 may include any number of func 

tions specific to GSN networks and GGSN components. For 

example, the GGSN EAM 240 may enable the UWAG 60 to 

support various GSM interfaces, such as GTP-u interfaces, 

GTP-c interface, and GTP' interface. Additionally, the 

GGSN EAM 240 may also include GGSN MIBs usually 

present within standard GGSNs. 

It should be understood that in the present embodiments, 

more that one protocol-specific EAM may be active simul 

taneously. Thus, the mobile node 12 may roam between 

networks that use different wireless access technologies, or 

the mobile node 12 may use multiple wireless access tech 

nologies at the same time. Additionally, the UWAG 60 can 

be implemented such that the protocol-specific EAMs 220, 

230, 240 are part of a software bundle, and that only certain 

ones are activated at a certain time, based on Software keys. 

For example, if a customer only buys the software keys for 

the PDSN EAM 220 and the 802.11 EAM 230, they will not 

be able to operate the system as a GGSN EAM 240 without 

also purchasing its respective software key. 

IV. Exemplary Data Structures for Use with an EAM 

FIG.3 shows an exemplary data structure 300 that may be 

stored within the UWAG 60 or another component (e.g., 

external database) in communication with the UWAG 60. 

The data structure 300 may keep track of data associated 

with the current wireless access technology being used by 

the mobile node 12. Furthermore, if the mobile node 12 

performs a handoff causing it to use a new wireless access 

technology, the data structure 300 may keep track of data 

associated with the new (transition) access technology that 

will be used by the mobile node 12. 

As depicted in FIG. 3, the data structure 300 may include 

any number of data blocks that are linked to one another by various pointers. In the present embodiment, the data struc 

ture 300 may include an active users list 310, a management 

pointer block 320, a first context data block 330 and a second 

context data block 340. 

A. Exemplary Active Users List 

The active users list 310 may correlate usernames or 

hardware identifiers (e.g., for mobile nodes) to pointers. Each pointer may then link to a management pointer block, 

Such as the management pointer block 320. Thus, each 

mobile node that accesses the UWAG 60 may have a 

corresponding management pointer block. To illustrate, in 

the present embodiment, the mobile node 12 may corre 

spond to user 2 within the active user list 310. As shown in 

FIG. 2, the pointer associated with user 2 links to the 

management pointer block 320. It should be understood that 

the active users list 310 may list any number of users, and 

that any number of pointers may be associated with each 

user. Furthermore, data included within other data blocks 

inside the data structure 300 may alternatively be stored 

within the active users list 310 and directly correlate to a username or hardware identifier. 

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B. Exemplary Management Pointer Block 

A management pointer block may include a pointer that 

links to data associated with the specific wireless access 

technology or “context in which a corresponding mobile 

node is operating. Additionally, a management pointer block 

may have a pointer that links to the data associated with a 

new (transition) wireless access technology that will be used 

when the mobile node performs a handoff. 

To illustrate, in the exemplary data structure 300, the 

management pointer block 320 may have an active context 

pointer that points to data associated with an active context 

(e.g., wireless access technology) that is being used by the 

mobile node 12. Additionally, the management pointer block 

320 may also include a transition context pointer which 

points to data associated with a transition context to which 

the mobile node 12 is switching. 

The transition context pointer may point to a NULL value 

if no transition (e.g., handoff) is taking place. Additionally, 

the active context pointer may point to a NULL value if a 

wireless access technology is currently not in use. Such as 

when the mobile node 12 is first turned on. 

In the present embodiment, the exemplary active context 

pointer within the management pointer block 320 may point 

to a first context data block 330. The first context data block 

330 may include data associated with the current wireless 

access technology used by the mobile node 12, which may 

be, for example, wireless Ethernet. Additionally, the exem 

plary transition context pointer within the management 

pointer block 320 may point to a second context data block 

340. The second context data block 340 may include data 

associated with a new wireless access technology (e.g., 

CDMA2000) that the mobile node 12 seeks to utilize. 

As will be described shortly, the pointers within the 

management pointer block 320 may switch the data blocks 

to which they point, depending on the state of the mobile 

node 12. Furthermore, it should be understood that alterna 

tively, the management pointer block 320 may include more 

or fewer pointers, or that data stored within the first and/or 

second context data blocks 330, 340 may instead be incor 

porated within the management pointer block 320. 

C. Exemplary Context Data Blocks 

As described earlier, the first and second context data 

blocks 330, 340 may include data relating to active and 

transition contexts of the mobile node 12. In the present 

embodiment, the first context data block 330 may include a 

data pointer block 332, an EAM data block 334, an account 

ing information data block 336, and a user profile data block 

338. Similarly, the second context data block 340 may 

include a data pointer block 342, an EAM data block 334, an 

accounting information data block 346, and a user profile 

data block 348. 

i. Exemplary Data Pointer Blocks 

As depicted in FIG. 3, the data pointer blocks 332, 342 

may include a set of pointers (e.g., EAM pointers, account 

ing information pointers, user profile pointers, etc.) that link 

to other data blocks 334–338 and 344–348 within the first 

and second context data blocks 330, 340, respectively. Additionally, each of the data pointer blocks 332, 342 may 

also include an EAM type block that describes the type of 

wireless access technology employed by the corresponding 

context data block 330, 340. To illustrate, the EAM type block within the data pointer block 332 may indicate “wire 

less Ethernet' if the mobile node 12 is currently using 

wireless Ethernet. Furthermore, the EAM type block within 

the data pointer block 342 may be “CDMA2000” if the 

mobile node 12 is transitioning to a CDMA2000 network. 

Case 2:23-cv-00444-JRG Document 1-4 Filed 09/27/23 Page 14 of 17 PageID #: 78
US 7,130,625 B2 

11 

Furthermore, each of the data pointer blocks 332, 342 may 

hold a connection state block that describes the current 

connection state (e.g., active operation, idle operation, etc.) 

for the corresponding context data block 330, 340. 

ii. Exemplary EAM Data Blocks 

In the present embodiment, the exemplary EAM data 

blocks 334, 344 may store data attributes that are specific to 

the wireless access technologies represented by the context 

data blocks 330, 340, respectively. For example, in the 

present embodiment, if the mobile node 12 is actively using 

wireless Ethernet, the EAM data block 334 may include data 

related to wireless Ethernet. Similarly, if the mobile node 12 

is roaming and seeks to use a different wireless protocol, 

such as CDMA2000, the EAM data block 344 within the 

transition context block may include data related to 

CDMA2OOO. 

Thus, the actual data stored within the EAM data blocks 

334, 344 may depend on the access technologies that the 

mobile node 12 is employing and/or transitioning to. For 

example, if the mobile node 12 is using and/or transitioning 

to an access technology that typically requires PPP. Such as 

CDMA2000 or UMTS, the corresponding EAM data block 

may include, for example, connection identification(s), the 

compression types (if any) being used, authorization infor 

mation, protocol setup/tear-down phases and States, and/or 

retry and timeout values. 

Alternatively, if the mobile node 12 is using and/or 

transitioning to an access technology that typically does not 

require framing, such as 802.11 or GPRS, the corresponding 

EAM data block may include, for example, protocol setup/ 

tear-down phases and states, dynamic host configuration 

protocol (DHCP) related information, ARP related informa 

tion, various network addresses (e.g., for the 802.11 access 

point 30), and/or the compression types (if any) being used. 

It should be understood that more or fewer data attributes 

may be included within the EAM data blocks 334, 344, and 

that the discussion here merely illustrates an exemplary 

embodiment. 

iii. Exemplary Generic Data Blocks 

As shown in FIG. 3, the first and second context data 

blocks 330, 340 may also include generic data blocks that 

provide information about the mobile node 12 that is not 

dependent on the type of wireless access technology that is 

being utilized. To illustrate, both context data blocks 330, 

340 may include accounting information data blocks 336, 

346, respectively. The accounting information data blocks 

336, 346 may include information such as accounting iden 

tifications, the number of the packets and bytes transmitted 

and received by the mobile node 12, pre-paid billing infor 

mation for the mobile node 12 (if appropriate), timestamps 

for connection times and connection durations of the mobile 

node 12, and so forth. Furthermore, the context data blocks 

330, 340 may also include user profile data blocks 338,348, 

respectively, which contain user profile information Such as 

a name, email address, and other such data that may be 

returned from the authentication server 90 during the 

authentication of the mobile node 12. 

It should be understood that any number of other generic 

data blocks may be included within the first and second 

context data blocks 330, 340. For example, generic data 

blocks providing information about the data transfer history 

of the mobile node 12 may alternatively be included within 

the context data blocks 330, 340. 

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D. Exemplary Data Block Sharing 

In alternate embodiments, pointers within various blocks 

may point to the same data block in order to save memory 

space. For example, FIG. 4 shows another exemplary data 

Structure 400 for use with the UWAG 60 that illustrates this 

point. The data structure 400 may include an active data list 

410, management pointer block 420, first context data block 

430, and second context data block 440, all of which may be 

substantially similar to their respective components 310, 

320, 330, 340 within the previous data structure 300. In the 

present data structure 400, however, the accounting infor 

mation blocks 336,346 may be replaced by a single account 

ing information block 450. Thus, the accounting information 

pointer within each of the shared data blocks 432, 442 may point to the same accounting information block 450. Such a 

mechanism may prevent duplicate data from taking up space 

in memory when two context data blocks share the same 

information. It should be understood from this example that 

any of the data blocks within the data structure 300 (e.g., 

user profile data blocks 438, 448) may be shared or linked 

to by more than one pointer. 

It should be further understood that in alternate embodi 

ments, the data structures 300, 400 may include more or 

fewer data blocks that may be implemented in different 

ways. For example, an alternate data structure may also 

include a third context data block to keep track of previous 

contexts used by the mobile node 12. Additionally, in an 

alternate embodiment, the data blocks may be implemented within a single linear data block as opposed to being 

connected via pointers. Furthermore, each of the blocks 

within the data structures 300, 400 may be implemented 

using hardware, software, or a combination of both. 

Additionally, in an alternate embodiment, during the setup 

of a new context data block (e.g., corresponding to a new 

wireless access technology), the UWAG 60 may wait for a 

threshold delay period before tearing down the old context 

data block (e.g., corresponding to an old wireless access 

technology). Thus, during the threshold delay period, the 

UWAG 60 and the mobile node 12 may communicate via the 

old and the new wireless access technologies. This mecha 

nism may be useful if a new wireless access technology being employed is not yet fully stable shortly after a handoff 

has been performed. 

V. Exemplary Switching Between Different Wireless Access 

Technologies 

FIGS. 5a-d show an exemplary embodiment of the 

UWAG 60 switching its active data block during a handoff 

to a different wireless access technology. In FIG. 5a, the 

active context pointer within the management pointer block 

320 points to the first context data block 330, which may correspond to, for example, a wireless Ethernet technology. 

Thus, the UWAG 60 and the mobile node 12 may be 

communicating using wireless Ethernet at this time. 

Additionally in FIG. 5a, the mobile node 12 is not in a 

potential handoff situation or transition state. Thus, the 

transition context pointer within the UWAG 60 may point to 

a NULL value 520, indicating that a transition to a new 

wireless access technology is not occurring because other 

wireless access technologies are not available or desirable to 

the mobile node 12 at this time. 

FIG. 5b shows when the mobile node 12 is roaming and 

encounters a viable wireless access technology (e.g., corre 

sponding to the second context data block 340) that is 

different than the one specified by the active context pointer 

(e.g., the first context data block 330). In such a scenario, the 

mobile node 12, the UWAG 60, and/or another component 

Case 2:23-cv-00444-JRG Document 1-4 Filed 09/27/23 Page 15 of 17 PageID #: 79
US 7,130,625 B2 

13 

within the wireless telecommunications network 10 may decide to perform a handoff to the new wireless access 

technology. Hence, in the present embodiment, the UWAG 

60 may instruct the transition context pointer within the 

management pointer block 320 to link to the second context 

data block 340, which may correspond to, for example, a 

CDMA2000 technology. As shown in FIG. 5b, the active 

context pointer may still point to the first context data block 

330, indicating that the mobile node 12 is still using wireless 

Ethernet at this time. 

In FIG. 5c, the transition context pointer and the active 

context pointer may Swap the data blocks to which they 

point. Thus, the transition context pointer may now point to 

the first context data block 330 (e.g., corresponding to 

wireless Ethernet), and the active context pointer may point 

to the second context data block 340 (e.g., corresponding to 

CDMA2000). Thus, the mobile node 12 may now commu 

nicate with the UWAG 60 using the wireless access tech 

nology specified within the second context data block 340 

(e.g., CDMA2000). Furthermore, since the handoff to the 

new wireless access technology is complete (i.e., the active 

context pointer has now been Switched to point to the second 

context data block 340), the transition pointer may now be 

switched to point back to the NULL value, as shown in FIG. 

Sd. 

Thus, the present paradigm enables a new wireless access 

technology to be set up before an old wireless access 

technology is torn down. After a new wireless access tech 

nology has been set up and the transition context pointer links to it, the active and transition context pointers may 

switch, and the old context data block (now pointed to by the 

transition context pointer) may be torn down on the side. 

Thus, the present embodiments may allow for a "seamless” 

handoff between a first wireless access technology and a 

second wireless access technology within a mobile node. 

It should be further understood that the present UWAG 60 

may support any number of calls from any number of mobile 

nodes simultaneously, and that the UWAG 60 may allocate 

bandwidth between the mobile nodes depending on the types 

of calls received. To illustrate, the UWAG 60 may, for 

example, statically allocate 50% of its capacity towards calls 

involving 802.11, 30% of its capacity towards calls involv 

ing CDMA2000, and 20% of its capacity towards calls 

involving GPRS or UMTS. Alternatively, the UWAG 60 

may perform dynamic bandwidth allocation depending on 

any number of different factors, such as the time of day, priority of calls received, available network resources, and so forth. 

The present embodiments may include a number of 

advantages. Allowing the Smooth transition from one wire 

less access technology to another enables the mobile node 

12 to roam to different areas that use different wireless 

technologies. Furthermore, the present embodiments enable 

a mobile node to roam between access technologies that 

have different framing requirements, such as those that 

typically require PPP (e.g., CDMA2000 and UMTS) and 

those that typically do not require framing (e.g., 802.11 and 

GPRS). Additionally, the present embodiments may enable a 

mobile node 12 or other network component to choose the 

most Suitable wireless access technology to use at any given 

time. To illustrate, the mobile node 12, UWAG 60, or other 

network component may evaluate any number of different 

factors, such as the type of application being run, the 

strength and cost of various available wireless technologies, 

and the desired call framing parameters, to determine which 

wireless access technology to use. 

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It should be understood that a wide variety of additions 

and modifications may be made to the exemplary embodi 

ments described within the present application. For example, 

any of the components within the wireless telecommunica 

tions network 10 may be implemented using software, 

hardware, and/or a combination of the two. It is therefore 

intended that the foregoing description illustrates rather than 

limits this invention and that it is the following claims, including all of the equivalents, which define this invention: 

What is claimed is: 

1. A method for seamlessly roaming between different 

wireless access technologies, the method comprising: 

providing a universal wireless access gateway with a 

shared component and a first environment access mod 

ule to establish a first wireless connection with a first 

network; 

communicating with the first network along the first 

wireless connection using a first wireless access tech 

nology: 

providing the universal wireless access gateway with a 

second environment access module: 

establishing a second wireless connection between the 

universal wireless access gateway and a second net 

work using the shared component and the second 

environment access module; and 

communicating with the second network along the second 

wireless connection using a second wireless access 

technology that differs from the first wireless access 

technology. 

2. The method of claim 1, wherein the first wireless access 

technology and the second wireless access technology com 

prise at least one of a wireless Ethernet technology, a 

Code-Division Multiple Access technology and a Global 

System for Mobile Communications technology. 

3. The method of claim 1 further comprising terminating 

the first wireless connection with the first network. 

4. The method of claim 3, wherein the step of terminating 

the first wireless connection occurs after the step of estab 

lishing the second wireless connection. 

5. The method of claim 1 further comprising switching 

seamlessly from communicating using the first wireless 

access technology to using the second wireless access tech 

nology. 

6. The method of claim 1, wherein the shared component includes functionality common to the first wireless access 

technology and the second wireless access technology. 

7. The method of claim 1, wherein the first environment 

access module includes functionality specific to the first 

wireless access technology, and the second environment 

access module includes functionality specific to the second 

wireless access technology. 

8. The method of claim 1 further comprising linking an 

active context pointer to a first context data block storing 

data associated with the first wireless access technology. 

9. The method of claim 8 further comprising linking a 

transition context pointer to a second context data block 

storing data associated with the second wireless access 

technology. 

10. The method of claim 9 further comprising switching 

the active context pointer and the transition context pointer. 

11. The method of claim 1, wherein the first wireless 

access technology and the second wireless access technol 

ogy use different framing mechanisms. 

12. The method of claim 11, wherein the first wireless 

access technology uses an Internet Protocol with a Point 

Case 2:23-cv-00444-JRG Document 1-4 Filed 09/27/23 Page 16 of 17 PageID #: 80
US 7,130,625 B2 

15 

to-Point Protocol and the second wireless access technology uses an Internet Protocol without the Point-to-Point Proto 

col. 

13. The method of claim 11, wherein the second wireless 

access technology uses an Internet Protocol with a Point 

to-Point Protocol and the first wireless access technology uses an Internet Protocol without the Point-to-Point Proto 

col. 

14. The method of claim 1, wherein a third network 

comprises the first network and the second network. 

15. The method of claim 1 further comprising a computer 

readable medium having stored therein instructions for 

causing a processor to execute the steps of the method of 

claim 1. 

16. A universal wireless access gateway comprising: 

a shared component; a first environment access module that communicates 

with the shared component to enable access to a first 

network using a first wireless access technology; and a second environment access module that communicates 

with the shared component to enable access to a second 

network using a second wireless access technology that 

differs from the first wireless access technology. 

17. The universal wireless access gateway of claim 16, 

wherein the first wireless access technology comprises a 

wireless Ethernet technology, and the second wireless access 

technology comprises a Code-Division Multiple Access 

technology. 

18. The universal wireless access gateway of claim 16 

further comprising a third environment access module that 

communicates with the shared component to enable access 

to the network that uses a third wireless access technology. 

19. The universal wireless access gateway of claim 18, 

wherein the first wireless access technology comprises a 

wireless Ethernet technology, the second wireless access 

technology comprises a Code-Division Multiple Access 

technology and the third wireless access technology com 

prises a Global System for Mobile Communications tech 

nology. 

20. The universal wireless access gateway of claim 16, 

wherein the shared component includes functionality com 

mon to the first wireless access technology and the second 

wireless access technology. 

21. The universal wireless access gateway of claim 16, 

wherein the first environment access module includes func 

tionality specific to the first wireless access technology, and 

the second environment access module includes functional 

ity specific to the second wireless access technology. 

22. The universal wireless access gateway of claim 16, 

wherein the first wireless access technology and the second 

wireless access technology use different framing mecha 

nisms. 

23. The universal wireless access gateway of claim 16, 

wherein a mobile node uses the universal wireless access 

gateway to communicate with at least one of the first 

network and the second network. 

24. The universal wireless access gateway of claim 23, 

wherein an authentication server communicates with the 

universal wireless access gateway while authenticating the 

mobile node. 

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25. The universal wireless access gateway of claim 16, 

wherein the universal wireless access gateway performs 

functionality specific to a packet data serving node and an 

802.11 roaming gateway. 

26. A method for seamlessly roaming between different 

wireless access technologies within a universal wireless 

access gateway, the method comprising: 

linking an active context pointer to a first context data 

block associated with a first wireless access technol 

Ogy, 

providing the universal wireless access gateway with a 

shared component and a first environment access mod 

ule to establish a first wireless connection with a first 

network; 

communicating with the first network along the first 

wireless connection using the first wireless access 

technology; 

providing the universal wireless access gateway with a 

second environment access module that is linked to the 

shared component; 

linking a transition context pointer to a second context 

data block corresponding to a second wireless access 

technology that differs from the first wireless access 

technology; 

Switching the active context pointer and the transition 

context pointer; 

establishing a second wireless connection between the 

universal wireless access gateway and a second net 

work using the shared component and the second 

environment access module; and 

communicating with the second network along the second 

wireless connection using the second wireless access 

technology. 

27. The method of claim 26, wherein the first wireless 

access technology and the second wireless access technol 

ogy comprise at least one of a wireless Ethernet technology, 

a Code-Division Multiple Access technology and a Global 

System for Mobile Communications technology. 

28. The method of claim 26 further comprising terminat 

ing the first wireless connection with the first network. 

29. The method of claim 26, wherein the shared compo 

nent includes functionality common to the first wireless 

access technology and the second wireless access technol 

Ogy. 

30. The method of claim 26, wherein the first environment 

access module includes functionality specific to the first 

wireless access technology, and the second environment 

access module includes functionality specific to the second 

wireless access technology. 

31. The method of claim 26, wherein the first wireless 

access technology and the second wireless access technol 

ogy use different framing mechanisms. 

Case 2:23-cv-00444-JRG Document 1-4 Filed 09/27/23 Page 17 of 17 PageID #: 81