Background and Objects of the Invention Mobile wireless communication is becoming increasingly important for providing safety, convenience, improved productivity, and simple conversational pleasure. One prominent mobile wireless communication option is cellular communication. Cellular phones, for instance, can be found in cars, briefcases, purses and even pockets.

In a mobile cellular telecommunications system, a mobile station normally communicates with the base station corresponding to the cell area in which the mobile station is located. There are circumstances, however, under which communication with the mobile station changes from one cell within the telecommunications network to another. A first situation is a handover operation in which the a mobile station roams into another cell while in a telephone call or other transaction. In order to choose a best cell for use by the roaming mobile station, signal strength measurements of cell signal transmissions are performed by the roaming mobile station. During the handover operation, various nodes in the network negotiate a cell change with the mobile station depending upon the nature of the handover.

A second situation in which communication with a mobile station or terminal changes from one cell to another is a part ofthe Idle Mode procedures ofthe terminal/mobile station.

This process, by which a terminal chooses which cell to utilize, is referred to as"camping on"a cell. The process includes location updating so that the serving mobile switching

center (MS C) and corresponding visitor location register (VLR) maintain the approximate <BR> <BR> location ofthe terminal. The"camping on"process may, for example, occurwhen aterminal is powered up. The camping process may also occur when a terminal is not engaged in a telephone call but is moving around and monitoring the transmission quality ofthe different cells. In the event theterminal changes location areas while monitoring the quality ofthe cell transmissions, the terminal will perform a location update.

For cellular phone system providers to offer cellular phone users new services, cellular wireless networks must be upgraded. To this end, there exist and/or are planned wireless telecommunication networks which are capable ofproviding both standard GSM services and IP based services and/or applications. One advantage provided by such networks is that they are backwards compatible. In other words, the network provides both GSM services and IP applications, such as VoIP, to terminals which are capable of accessing IP based applications while at the same time maintaining conventional GSM wireless communication services for terminals which cannot utilize IP applications, such as due to limitations of the terminal itself.

One IP based application which is accessible by cellular telephone users is voice over IP (VoIP). The VoIP application provides quality voice communications over the packetized Internet. VoIP, over the current Internet, for example, can provide acceptable voice communications at a greatly reduced cost to the user, when compared to traditional mobile telephone tolls.

Although capable of providing telecommunication services to many subscribers, the above-described wireless network is not without its shortcomings. For instance, if a caller wishes to make a call in a wireless network having a VoIP application, a circuit switched call is transmitted from the corresponding Base Station System to the Mobile Switching Center (MSC), which is then sent along a trunk from the MSC to a gateway connected to an Internet Service Provider (ISP). The gateway converts the call from a circuit switched voice call to a packet switched call for transmission on the Internet. Although this method ofutilizing the Internet realizes reduced call tariffs, the VoIP call nonetheless utilizes circuit switch transmission resources in handling the call. Accordingly, there is a need for placing

the point at which access is made to the Internet closer to the terminal and/or mobile station within the mobile communications network.

One approach is to place an interface for accessing the Internet within the Base Station Controllers (BSC) so that the switching circuitry of the network is substantially bypassed when an IP based application is provided to a mobile station user. In a communications network utilizing this approach, some ofthe cells in the network may be capable of providing IP based applications and/or communications, such as VoIP, in addition to conventional GSM based communication. A call placed by a terminal and/or mobile station served by these cells, for example, is capable of being transported over/through the Internet so as to incur a relatively inexpensive toll. Because not every B SC in the mobile network will typically possess the capability to provide IP based services and/or applications to mobile stations served thereby, there exists a need for ensuringthat terminals requesting an IP based service are satisfactorily and cost effectively served.

It is an object ofthe present invention to provide a communications system in which the cell assignment to a terminal is dependent upon user preference.

It is another object ofthe present invention to provide such a communication system having enhanced communication of both network and terminal information between the network and a terminal therein.

SUMMARY OF THE INVENTION The present invention overcomes shortcomings in existing communication systems and satisfies a significant need for a communication system having improved methods for accessing the system's IP based capabilities.

According to the present invention, there is provided a mobile communications network, such as, for example, a Public Land Mobile Network (PLMN), divided into a number of cells which communicate with at least one MSC via a number of base stations. At least one base station is capable of accessing an IP based application, such as VoIP by including a transcoder to convert a voice call transmitted by a terminal into a packet switched call for transport over the Internet. The cells associated with each base station

transmit their service capabilities, including its IP-based capabilities, so that a terminal receiving the transmission is aware of the service capabilities of its present cell and neighboring cells. Conversely, each terminal in the mobile communications network transmits its own capabilities, such as being IP capable, to the network. In this way, both the network and each terminal can be apprised of each other's capabilities so that decisions pertaining to providing service-related activities, such as transporting a telephone call, are effectively carried out.

The present invention further includes each terminal possessing an interface and necessary circuitry to facilitate the user in selecting a cell preference from among cells which only support GSM-related services and cells which support both GSM-related services and IP based applications. For example, the interface may allow the user to prefer cells which support VoIP for transporting telephone calls placed by the user's mobile station over the Internet. The system selects a cell for providing a service to the terminal, such as transporting a telephone call placed thereby, based in part upon the service-related capabilities of cells in the immediate area of the terminal and upon the selected cell preference. As a result, the present communications system suitably matches its available services to the user's service preferences.

BRIEF DESCRIPTION OF THE DRAWINGS A more complete understanding ofthe present invention may be had by reference to the following detailed description when taken in conjunction with the accompanying drawings wherein: Figure 1 is a block diagram of a telecommunications system according to the present invention; Figure 2 is a block diagram of a terminal according to the present invention ; Figure 3 is a flow chart illustrating a handover operation in association with the present invention; Figure 4 is a flow chart illustrating a cell reassignment operation in association with the present invention; and

Figure 5 is a flow chart illustrating a location update operation in association with the present invention. <BR> <BR> <P>DETAILED DESCRIPTION OF THE PREFERRED EXEMPLARY EMBODIMENTS The present invention will now be described more fully hereinafter with reference to the accompanying drawings in which a preferred embodiment ofthe invention is shown.

This invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Referring to Figures 1 and 2, there is shown a communications system 1 including mobile communications network 2 and Internet and/or IP network 3. Mobile communications network 2 may preferably include a plurality of interconnected MSCs 4, each of which communicates with one or more base station controllers (BSC) 5. Each BSC 5 communicates with at least one base transceiver station (BTS) 6. A single BTS 6 serves one or more cells in mobile communications network 2. The operation of mobile communications network 2 and in particularthe interrelationship between MSCs 4, BSCs 5 and BTSs 6 in providing mobile cellular services are known in the art and will not be described herein for reasons of simplicity.

One or more BSCs 5 of mobile communications network 2 may be capable of accessing IP network 3 in order to provide one or more IP applications to subscribers of the mobile communications network 2. A BSC 5 may, for example, have access to IP network 3 using one or more Internet Service Providers (ISP) 7.

One IP application which a BSC 5 preferably accesses and is capable of providing to subscribers of mobile communications network 2 is VoIP, which provides acceptable voice communications at a greatly reduced subscriber cost, as explained above.

Accordingly, the BSCs 5 which are capable of providing VoIP to subscribers ofthe mobile communications network 2 include a transcoder unit 8 or other device which converts a

circuit switched (GSM) voice call to a packet switched call fortransport overthe Internet.

By including transcoder unit 8 within a B S C 5, a VoIP telephone call placed by a terminal 9, such as a mobile station, bypasses the switching circuitry (MSCs 4) of mobile communications network 2.

It is understood that a cell may be capable of accessing a number of IP based applications in addition to VoIP through its corresponding B SC 5. For instance, a cell in mobile communications network 2 may be capable of accessing an H. 323 based multimedia application.

The present invention allows subscribers of mobile communications network 2 to more effectively access communication services provided by mobile communications network 2 and IP network 3. It is understood that not every BSC 5 may be capable of accessing IP network 3. It is also understood that a BSC 5 which may be capable of accessing IP network 3 may typically be capable of accessing a limited number of IP applications. For instance, an IP capable BSC 5 may utilize a specific ISP 7 in accessing IP network 3. Due to the fact that BSCs of mobile communications network 2 and thus the cells corresponding thereto provide different IP applications and/or possess different IP based capabilities, the present invention allows a subscriber of mobile communications network 2 to select preferred capabilities for a cell to possess in order to communicate therewith.

Specifically, the present invention allows a subscriber to identify a preference for acellBSC which supportsparticularIPbased applicationswithwhichthe subscribermay communicate. The mobile communications network 2 utilizes the identified cell preference in selecting a cell to communicate with the subscriber's terminal 9, such as when mobile communications network 2 performs cell handover procedures or while camping-on a cell.

To facilitate the process of selecting a cell preference and assigning a cell to communicate with a terminal 9, information regarding network 2 is preferably transmitted to terminal 9. The information transmitted by mobile communications network 2 to a terminal 9 preferably informs terminals 9 ofthe capabilities of each cell. In other words, for each cell, mobile communications network 2 provides a list of services and/or applications,

including IP based applications, which are accessible thereby. In a preferred embodiment ofthe present invention, the Broadcast Control Channel (BCCH) is modified to include this cell capability information. In this way, a terminal 9, upon receiving the cell capability broadcast, is capable of determining the cell capabilities ofthe cell presently serving terminal 9 and its neighboring cells.

As stated above, the present invention allows for the selection of a cell preference for use in assigning a terminal 9 to a cell within mobile communications network 2. Referring to Figure 2, terminal 9 preferably includes an interface 20 which is coupled to transceiver 21 to receive the BCCH information pertaining to cell capabilities and to generate the necessary signals for presenting the cell capabilities to the subscriber on display 22. Display 22 preferably further displays the presently assigned cell, its capabilities, and/orthe service being provided to the subscriber.

Further, terminal 9 allows for the selection or identification of a cell preference for use in assigning terminal 9 to a cell, such as during a handover procedure or while camping- on a cell. The cell preference may be entered into terminal 9 bythe subscriberusingkeypad 23. Alternatively, the cell preference maybe stored, either permanently or otherwise, on a SIM card 24 which is operatively connectible to terminal 9. By possessing a number of SIM cards having stored thereon different cell capability preferences, terminal 9 maybe configured with different cell capability preferences simply by inserting different SIM cards 24 therein.

The present invention allows mobile communications network 2 (Figure 1) to determine the capabilities of terminals 9 located therein. In particular, a terminal 9 preferably communicates to mobile communications network 2 its IP based capabilities.

For example, the information may indicate whether terminal 9 complies with a certain suite of specifications, such as H. 323 or SIP. Terminal capability information may be utilized by mobile communications network 2 in reaching cell assignment decisions, such as during cell handover or camping on a cell, by giving greater preference to assigning an IP capable cell to a terminal 9 which prefers communication with an IP capable cell and which itselfis IP capable. Specific channel types or target cells could be selected for assignment to a

terminal 9 based upon the terminal capability information. In a preferred embodiment ofthe present invention, the IP based capabilities of a terminal 9 are added to the GSM classmark corresponding to terminal 9 for communication to mobile communications network 2.

In addition, the subscriber profile, stored in a Home Location Register (HLR) 10, may preferably indicate whether IP support for a terminal 9 is preferred or forbidden. This profile information may be downloaded and used together with the terminal capability information in the classmark in assigning a cell to serve terminal 9.

The operation of the present invention will now be described with reference to Figures 3-5. In performing a cell handover operation in which cell selection is based in part upon the user's communication preferences, terminal 9 monitors the signal strength of cells in the area thereof at step 3 0. In the event one or more cells whose transmissions terminal 9 measured is a preferred cell or otherwise possesses preferred communication capabilities, terminal 9 sends preferred cell capability information to mobile communications network 2 at step 31. For example, terminal 9 may send a cell preference listing to mobile communications network 2. Next, if mobile communications network 2 determines that, based upon the preferred cell information sent by terminal 9, the new cell for communicating with terminal 9 is associated with a different BSC 5, then the channel preference corresponding to the cell capability preferences is sent to the B SC 5 corresponding to the new cell at step 32. In this way, BSC 5 is aware of the preferred channel type and equipment which is needed to support it.

It is noted that the serving MSC 4 may not know the preferred channel type corresponding to the preferred cell capability preference terminal 9. Consequently, MSC verifies that the preferred cell capability for the best cell is possible at step 33. If the preferred cell capability preference is not possible and/or compatible, then the handover operation to the selected cell is rejected at step 34. Alternatively, if it is determined that the preferred cell capability preference is possible for the best cell, then terminal 9 is handed over thereto at step 35.

Figure 4 illustrates the process for selecting a cell for terminal 9 while"camping on" a cell. Initially, each base transceiver station (BTS) 6 broadcasts the IP capabilities, if any,

for the cells corresponding thereto for reception by terminal 9 at step 41. Next, interface 20 interprets the cell IP capability information and displays the information on display 21 at step 42. At this point, a cell capability preference may be identified at step 43. This identification may be undertaken by the subscriber manually entering the cell capability preference using terminal keypad 23 or by terminal 9 reading the cell preference from SIM card 24 connected thereto.

In the event terminal 9 has indicated to mobile communications network 2 that terminal 9 is to be camped onto a cell selected or preferred thereby, then terminal 9 is camped onto the selected cell at step 44. If the cell camped onto during step 44 is in a new location area, then a location update is performed at step 45.

The steps for performing a location update in the serving MSC 4 and corresponding VLR is illustrated in Figure 5. Upon a reception location update request from terminal 9 at step 51, MSC 4 receives and stores the classmark therefor at step 52. The classmark may include cell capability preference information for terminal 9. If it is determined that terminal 9 is not registered with MSC 4, MSC 4 notifies the HLR 10 corresponding to terminal 9.

HLR 10 thereupon sends data pertaining to terminal 9 and including its cell capability preferences to MSC 4 at step 53. Thereafter, the subscriber profile for terminal 9 is stored within MSC 4 and/or its corresponding VLR at step 54.

Although the preferred embodiments of the system and method of the present invention have been illustrated in the accompanying drawings and described in the foregoing detailed description, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the spirit ofthe invention as set forth and defined by the following claims.