EP1151583A1

EP1151583A1 - Envelope message for transparent transmission through ip network

Info

Publication number: EP1151583A1
Application number: EP00908530A
Authority: EP
Inventors: Janette Chen Lin
Original assignee: Ericsson Inc
Current assignee: Ericsson Inc
Priority date: 1999-02-16
Filing date: 2000-02-07
Publication date: 2001-11-07
Also published as: CN1340259A; AU2985500A; WO2000049773A1

Abstract

A method, system, and mechanism for transparently transmitting network-specific information (58) of a network (72) through an Internet Protocol (IP) network (44). The IP network (44) includes a first (42, 68) and second (46, 70) endpoint, where the network (72) is served by the first endpoint (42, 68) of the IP network (44). An envelope message (60) is defined, where the envelope message (60) contains the network-specific information (58) and a tag (62) indicating to the IP network (44) to pass the envelope message (60) and network-specific information (58) through the IP network transparently. The envelope message (60) may also include a message type indicator (62) and the length (64) of the network-specific information (58). The network (72) may be an originating or terminating wireless cellular network.

Description

Envelope Message for Transparent Transmission Through IP Network

TECHNICAL FIELD

This invention relates generally to communication systems, and more particularly

to a method, system and mechanism for transparently transmitting network-specific

information through an Internet Protocol (IP) network.

BACKGROUND OF THE INVENTION

Wireless communication technology has experienced unprecedented growth,

fueled by advances in radio frequency, satellite, and microelectronic technologies and by

the convenience of access to telephony and portable cellular devices. A common

architecture for wireless communication is the Global System for Mobile

Communications (GSM) which is a protocol standard defined by the Conference of

European Posts and Telegraphs (CEPT) for use in digital land mobile radio networks.

Figure 1 shows the layout of a generic GSM network 10 comprised of three main parts: a

mobile handset 12, a Base Station Subsystem (BSS) 14, and network subsystem 16.

Mobile handset 12 is typically a cellular telephone that is carried by the

subscriber, although other terminal devices such as lap-top computers or fax machines

may be used to communicate information over the GSM network 10. The network

subsystem 16, the main part of which is the Mobile Switching Center (MSC) 30, performs the switching of calls between the mobile user and other fixed or mobile

network users, as well as mobility management. The mobile handset 12 and the BSS 14

communicate with one another across the Um interface 18, also known as the air interface

or radio link, which is controlled by the BSS 14. The BSS 14 communicates with the

MSC 30 of network subsystem 16 across an A-interface 20.

The Base Station Subsystem (BSS) 14 comprises two parts: the Base Transceiver

Station (BTS) 26 and the Base Station Controller (BSC) 28. BTS 26 communicates

across the standardized Abis interface 30 with BSC 28, allowing operation between

components. BTS 26 houses radio transceivers that define a cell and handles the radio-

link protocols with the mobile handset 12. In a large urban area, there may be a large

number of BTSs 26 deployed. BSC 28 manages the radio resources for one or more

BTSs 26, and, as such, there may be several BSCs 28 within a single BSS 14. Among the

functions of the BSC 28 are radio-channel setup, frequency hopping, and handovers.

BSC 28 provides a connection mechanism between the mobile handset 12 and the MSC

30 of network subsystem 16 which acts as the interface to one or more fixed networks 32.

The central component of the network subsystem 16 is the Mobile Switching

Center (MSC) 30, which acts like a normal switching node of the Public Switched

Telephone Network (PSTN), and provides all the functionality needed to handle a mobile

subscriber, such as registration, authentication, location updating, handovers, and call

routing to roaming subscribers. These functions are provided in conjunction with several other network entities, which together form the network subsystem 16. The MSC 30

provides the connection mechanism to the fixed networks 32 which may include the

PSTN or an Integrated Service Digital Network (ISDN), for example. The Home

Location Register (HLR) 34 and Visitor Location Register (VLR) 36, together with the

MSC 30, provide call routing and roaming capabilities for the GSM network 10. In

particular, the HLR 34 contains administrative information of the subscriber registered in

the corresponding GSM network 10, along with the current location of the mobile

handset 12. Likewise, the VLR 36 contains selected administrative information from

HLR 34 necessary for call control and provisioning of the subscriber services for each

mobile currently located in the geographical area controlled by the VLR 36. Other

registers are used for authentication and security functions within the network subsystem

16.

The Internet has become a popular tool for sending and receiving information. In

essence, the Internet comprises a worldwide network of communications equipment and

service providers which use a common protocol for communicating. On the Internet,

messages are transmitted from one user to another over a vast infrastructure of routers,

servers, gateways and other similar devices. Typically, users on either end of the network

operate computers equipped with appropriate software, devices and other components.

Examples of such components include a modem and Internet browser application. Often,

a user establishes a connection to the Internet through an Internet Service Provider (ISP). The underlying link level protocols stacks handle the messaging functions on both ends

of the channel.

The widespread use of the Internet as a communications tool has led to an intense

push for the integration of Internet services with other networks such as cellular networks

including GSM. Protocols such as H.225 and H.245 are communications protocols

proposed by the International Telecommunication Union (ITU) as standards for

transmission of non-telephone signals over LANs such as the Internet.

SUMMARY OF THE INVENTION

The present invention achieves technical advantages as a method, system and

mechanism for transparently transmitting network-specific information through an IP

network by defining an envelope message containing network-specific information and

passing the envelope message through the IP network. The present invention provides a

means for transmitting network-specific information over the Internet without Internet

devices or nodes attempting to parse the network-specific information in the envelope

message, which may contain proprietary data specific to the originating network.

In one embodiment, disclosed is a method of providing network-specific

information of a first network served by a first endpoint of an Internet Protocol (IP)

network to a second network served by a second endpoint of the IP network. The method

includes the step of defining an envelope message, where the envelope message contains the network-specific information and indicates to the IP network to pass the network-

specific information through the IP network transparently, i.e. without parsing the data

inside the envelope message.

In another embodiment, disclosed is a system for transparently transmitting

network-specific information of a first network through an IP network. The system

includes a first endpoint communicably coupled to the first network and the IP network,

and a second endpoint coupled to the IP network. The first endpoint comprises an

enveloping means adapted to define an envelope message. The envelope message

contains the network-specific information and indicates to the IP network to pass the

network-specific information in the envelope message through the IP network to the

second endpoint transparently.

Also disclosed is a mechanism for providing network-specific information of a

first network to an IP network. The mechanism is communicably coupleable to the first

network and comprises an envelope generator adapted to define an envelope message.

The envelope message contains network-specific information and indicates to the IP

network to pass the network-specific information and the envelope message through the

IP network transparently.

Advantages of the invention include the ability to transparently transmit

proprietary information that is specific to an originating or terminating network across an

IP network without having the proprietary information parsed by terminals or devices in the IP network, which may misinterpret or may not be concerned about the information.

The invention provides improved security and prevents losing information due to

translation problems between the IP network and originating and terminating networks.

Features of the originating and terminating networks may be enhanced or created, with

the ability to pass network-specific information transparently, provided by the present

invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above features of the present invention will be more clearly understood from

consideration of the following descriptions in connection with accompanying drawings in

which:

Figure 1 illustrates a GSM network 10 of the prior art;

Figure 2 illustrates a GSM network 40 in communication with an IP network 44

in which the present invention may be employed;

Figure 3 illustrates an IP network 44 having a plurality of endpoints and a

gatekeeper;

Figure 4 illustrates an embodiment of the present invention with an IP network 44

in communication with two GSM networks 72 and 74 through IP point of presences 42

42 and 46; Figure 5 shows a conceptual diagram of the envelope message 60 of the present

invention; and

Figure 6 illustrates a preferred embodiment of the present invention with IP

network 44 utilizing H.225 in communication with GSM networks 72 and 74 through

Network Access Controller (NAC) 68 and 70, respectively.

Corresponding numerals and symbols in the different figures refer to

corresponding parts unless otherwise indicated.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

— Referring to Figure 2, illustrated is a GSM network 40 in communication with an

Internet Protocol (IP) network 44 through an endpoint or IP point of presence 42. In the

architecture shown, a cellular voice or data call may be initiated by the mobile station 12,

communicated through BTS 26 and BSC 28 to the IP point of presence 42, and routed to

another endpoint in the IP network 44, as will be shown shortly. A current problem with

placing a call or transmitting data from an originating communication network such as

the GSM network 40 over the IP network 44 is that some GSM network 40 information

in the transmission is uninterpretable by the IP network 44 devices, for example, a

gatekeeper in the IP network 44 (not shown). Attempting to convert radio protocols to IP

protocols results in the loss of data and missing information due to the limitation of the

communication protocols used by the IP point of presence 42 and other nodes in the

network 44.

Information sensitive to transmission over the IP network 44 may include various

types of network-specific information from an originating or terminating network. In the

GSM network 40, for example, such proprietary information may include which cell the

mobile station 12 is using, at what frequency the mobile station 12 is operating, the kind

of codec used, or other radio-specific information subject to misinterpretation or that may

be unreadable or undecipherable by the IP network 44. In other networks, other

information may be proprietary to the network; such as in a banking system, the information may include credit card application information, loan application

information, or other types of information that is unable to be deciphered by devices in

the IP network 44, due to limitations in IP protocols.

Figure 3 illustrates a block diagram of an IP network 44, having two endpoints 42

and 46 in communication with one another through a gatekeeper 48. The endpoints 42

and 46 may comprise a gateway, a voice gateway, or other means of entry into the IP

network 44, and are herein referred to as an IP point of presence. The gatekeeper 48 is a

node in the IP network 44 such as a personal computer or router that controls the routing

of information between endpoints. In this architecture, information is transmitted from IP

point of presence 42 to the gatekeeper 48 and on to IP point of presence 46 in the IP

network 44 which is within the same gatekeeper 48 zone.

Figure 4 illustrates an embodiment of the present invention where information

from non-IP networks 72 and 74 is transmitted over the IP network 44 through a

respective endpoint or IP point of presence 42 and 46. As depicted, an originating data

transmission or call request is initiated by mobile station 12, and may comprise voice or

digital data. The data transmission or call request is transmitted from the mobile station

12 to the BTS 26 which transmits the request to BSC 28, where the request is forwarded

to IP point of presence 42 over the A-interface 20. Each of the devices including mobile

station 12, BTS 26 and BSC 28 may contribute information particular to the cellular

network they are operating in, creating originating network-specific data or information 58. The network-specific information 58 may include, for example, which cell the

mobile station 12 is using, at what frequency it is operating, the kind of codec in use, or

any other kind of radio-specific information. The origination network information 58 is

meaningful only to the IP point of presence 42 and 46, not to the gatekeeper 48 or other

nodes in the IP network 44.

In accordance with the present invention, the IP point of presence 42 defines an

envelope message 60 in a suitable format with a tag or message type field 62 indicating

that the envelope message 60 containing the originating network-specific data or

information 58 is to be transmitted through the IP network 44 without the IP network 44

devices attempting to parse, or translate the envelope message 60 containing network-

specific information 58 from the GSM network 72, i.e. the information 58 is to be

transmitted transparently. The IP point of presence 42 then transparently transmits the

envelope message 60 to the gatekeeper 48, where the envelope message 60 is then

transmitted to another endpoint within the IP network 44 such as IP point of presence 46.

IP point of presence 46 is in communication with and serves another GSM network 74,

and the envelope message 60 is transmitted over A-interface 50 to BSC 52, where the

envelope message 60 is forwarded to BTS 54 and then to mobile station 56. The

originating network information 58 remains unparsed by the devices such as gatekeeper

48 of the IP network 44 during transmission, preventing translation errors and dropped or

missing information that may result. The envelope message 60 may be transmitted or passed on transparently to any

other-gateway or node in the IP network and then on to other communication systems,

such as the Public Switched Telephone Network (PSTN) or other private communication

networks, (not shown) for example. The originating network information may be read

and used by a terminating network utilizing the same communication format, for

example, another GSM or wireless cellular network. The teachings and principles of the

present invention also apply to sending network-specific information from terminating

networks transparently through an IP network 44 in a like manner.

Figure 5 is a conceptual diagram of the envelope message 60 in accordance with

the present invention. First, the message type parameter or field 62 is contained within

and forms a part of the envelope message 60. The message type parameter 62 may be a

number, for example, "35" that distinctively indicates to the gatekeeper 48 that the

message is an envelope message 60. This particular number may be assigned within the

IP network 44 communication protocol, for example. The envelope message 60

preferably includes a length field 64 that indicates the length of the originating network-

specific data 58 to follow. The next field in the envelope message 60 contains the

originating network-specific data 58 having the length indicated in length field 64.

Preferably, the envelope message 60 is generated within the IP point of presence 42, in

accordance with the present invention. Figure 6 illustrates a preferred embodiment of the present invention. The IP

network 44 utilizes the H.225 call control protocol which uses Q.931 user-to-network

protocol, and the IP point of presences to the IP network 44 comprise Network Access

Controllers (NACs) 68 and 70 complying with H.323 device protocol. The envelope

message 60 of the present invention is suitable for use within the H.225 and Q.931

protocols to avoid missing information due to limitations of H.225 and Q.931 protocols,

which are designed to only support user-to-network scenarios.

A data transmission or call request may be initiated by mobile station 12 and sent

to BTS 26, to BSC 28 and then over A-interface 20 to NAC 68. One or all of the devices

contribute to the creation of originating network-specific data 58, which will be passed

transparently through the IP network 44 to a terminating GSM network 74 in accordance

with the present invention. The NAC 68 defines an envelope message 60, preferably

attaching a message type field 62 and length field 64 to the originating network-specific

data 58 of the transmission request by the mobile station 12. In H.225 protocol, the

message type field 62 is 2 bits, and the length field 64 is 8 or 16 bits, for example.

One side of the NAC 68 is capable of communicating via the A-interface 20 of the

GSM network 72 with mobile station 12, while the other side of the NAC 68

communicates with the gatekeeper 48 via H.225 (Q.931) protocol. The envelope

message 60 is then transmitted by the NAC 68 to the gatekeeper 48 where the envelope

message 60 is understood by recognition of the message type 62 to be sent transparently. The gatekeeper 48, also communicating using the H.225 protocol, then transmits the

envelope message 60 to NAC 70, also an H.225 protocol device, which is capable of

using and interpreting the originating network- specific data 58. The envelope message

60 and originating network data 58 is transmitted to terminating GSM network 74 over

A-interface 50 to BSC 52, BTS 54 and mobile station 56. The envelope message 60 may

also be passed on to other nodes in the IP network 44 such as gateway 76 and on into the

Public Land Mobile Network (PLMN) 78 or (PSTN) (not shown), for example.

Network-specific information from terminating networks may be transmitted

transparently through the IP network 44 in a like manner, in accordance with the present

invention.

Preferably, the envelope message 60 contains a complete A-interface message and

is initiated and formed by the sending NAC 68. The gatekeeper 48 is capable of

recognizing the envelope message 60 and understands to transparently transfer the

envelope message 60 to its destination without parsing the envelope message 60.

The novel method and system of the present invention achieves technical

advantages by utilizing an envelope message to transparently transmit information from

one endpoint to another endpoint of the Internet, providing the advantage of preventing

missing information from data transmission and call requests. Also provided is the

ability to transparently transmit information from an originating or terminating non-IP

network, such as the GSM network 72, through an IP network 44 to a terminating or originating network. Further provided is the ability to enhance or create improved

features of the originating and terminating networks, due to the information not being

parsed by the IP network 44 devices.

While the invention has been described with reference to illustrative

embodiments, this description is not intended to be construed in a limiting sense. Various

modifications in combinations of the illustrative embodiments, as well as other

embodiments of the invention, will be apparent to persons skilled in the art upon

reference to the description. For example, other protocols than H.225 protocol may be

used and would benefit from the present invention. Additionally, data networks other

than wireless cellular networks may transmit information over an IP network in

accordance with the present invention. For example, the originating network 72, which

may alternatively be a terminating network, may comprise a banking system rather than a

GSM network. The data specific to a banking system may include credit card

information, customer credit data, bank account balances, loan application information,

and other data specific to the particular data system. It is therefore intended that the

appended claims encompass any such modifications or embodiments.

Claims

What is claimed is:

1. Armethod of providing network-specific information of a first network served by a first

endpoint of an Internet Protocol (IP) network to a second network served by a second

endpoint of said IP network, said method comprising the step of:

defining an envelope message, wherein said envelope message contains said

network-specific information and indicates to said IP network to pass said network-

specific information in said envelope message through said IP network transparently.

2. The method of Claim 1 wherein said envelope message includes information regarding

the length of said network-specific information.

3. The method of Claim 1 wherein said envelope message includes a tag indicating a

message type.

4. The method of Claim 1 wherein said originating network is a wireless cellular

network.

5. The method of Claim 4 wherein said envelope message includes an A-interface

message.

6. The method of Claim 4 wherein said first network is a Global System for Mobile

communications (GSM) network.

7. The method of Claim 6 wherein said GSM network utilizes H.225 protocol and

wherein said first and second endpoints are H.323 endpoints.

8. The method of Claim 6 wherein said first endpoint is a Network Access Controller

(NAC) comprising a Mobile Switching Center (MSC) in said GSM network.

9. The method of Claim 1 wherein said first network is a banking system.

10. The method of Claim 1 wherein said IP network comprises a gatekeeper, wherein

said gatekeeper transparently routes said envelope message from said first endpoint to

said second endpoint.

11. The method of Claim 1 wherein said envelope message is defined by said first

endpoint.

12. The method of Claim 1 wherein said envelope message is packetized.

13. The method of Claim 1 wherein said first network is an originating network and said

second network is a terminating network.

14. The method of Claim 1 wherein said first network is a terminating network and said

second network is an originating network.

15. A system for transparently transmitting network-specific information of a first

network through an Internet Protocol (IP) network, said system comprising;

a first endpoint communicably coupled to said first network and said IP network;

and

a second endpoint coupled to said IP network, wherein said first endpoint

comprises an enveloping means adapted to define an envelope message, said envelope

message containing said network-specific information and indicating to said IP network

to pass said network-specific information in said envelope message through said IP

network to said second endpoint transparently.

16. The system according to Claim 15 wherein said enveloping means is adapted to

define the length of said network-specific information in said envelope message.

17. The system according to Claim 16 wherein said enveloping means is adapted to

define a message type in said envelope message.

18. The system according to Claim 15 wherein said IP network comprises a gatekeeper,

wherein said envelope message is passed from said first endpoint to said second endpoint

through said gatekeeper.

19. The system according to Claim 15 wherein said envelope message is packetized.

20. The system according to Claim 15 wherein said first network is a wireless cellular

network.

21. The system according to Claim 20 wherein said envelope message contains an A-

interface message.

22. The system according to Claim 15 wherein said cellular network is Global System

for Mobile communications (GSM).

23. The system according to Claim 22 wherein said GSM utilizes H.225 protocol and

wherein said first and second endpoints are H.323 endpoints.

24. The system according to Claim 22 wherein said first endpoint is a Network Access

Controller (NAC) comprising a Mobile Switching Center (MSC) in said GSM network.

25. The system according to Claim 15 wherein said first network is a banking system.

26. The system according to Claim 15 wherein said first network is an originating

network.

27. The system according to Claim 15 wherein said first network is a terminating

network.

28. A mechanism for providing network-specific information of a first network to an

Internet Protocol (IP) network, said mechanism communicably coupleable to said first

network and comprising;

an envelope generator adapted to define an envelope message, wherein said

envelope message contains said network-specific information and indicates to said IP

network to pass said network-specific information in said envelope message through said

IP network transparently.

29. The mechanism according to Claim 28 wherein said envelope generator is adapted to

include information indicative of the length of said network-specific information and

information indicative of the message type in said envelope message.

30. The mechanism according to Claim 28 wherein said envelope message is packetized.