HK1075348B - Method and apparatus for configurable selection and acquisition of a wireless communications system - Google Patents

Description

Method and apparatus for configurable selection and acquisition for wireless communication systems

Related application

This patent application claims priority to U.S. provisional patent application No. 60/354,424, filed on 4/2/2002.

Technical Field

The present invention relates generally to wireless communications, and more particularly to a method and apparatus for configurable selection and acquisition for a wireless communication system.

Background

A mobile device may often access more than one wireless communication system within its geographic area. The quality of wireless service available to a mobile device may vary from system to system depending on the equipment used by each system, the characteristics of the mobile device, the distance between the mobile device and the local base station, physical obstructions such as buildings and hills, and the amount of communication traffic for each system. The local wireless communication system may also support different multiple access wireless communication protocols, such as: code Division Multiple Access (CDMA), wideband CDMA (wcdma), Advanced Mobile Phone Service (AMPS), global system for mobile communications (GSM), General Packet Radio Service (GPRS), or High Data Rate (HDR) technologies (e.g., 1xEV technologies). In addition, the fee charged to the user of the mobile device may vary depending on the time of day, the duration of the connection with the wireless communication system, and whether the mobile device is listed as a subscriber to the wireless communication system.

In operation, a conventional mobile device selects and attempts to acquire and register with at least one available wireless communication system. To assist in the selection of the desired system, the mobile device typically stores some system data that identifies those wireless communication systems with which the mobile device is compatible. In one method, the system data is a Preferred Roaming List (PRL) that includes a system table that stores System Identifiers (SIDs) and Network Identifiers (NIDs) for each wireless communication system and an acquisition table that stores acquisition parameters including frequency bands, frequencies, and modes for the systems listed in the system table.

Within the system table, wireless communication systems are often grouped by geographic region and sorted from most desirable to least desirable system in each region. The most desirable system in a particular geographic area is typically the subscriber system, but may also be a roaming system that provides an advantageous combination of low cost and high quality services to mobile devices. Roaming systems typically provide wireless service to non-subscriber mobile devices at a much higher cost than subscription service, and may be desirable when a mobile device enters a geographic area outside the coverage area of the mobile device's subscription service, when subscription service is interrupted or unavailable, or when the available subscription service is at an unacceptably low quality level. The system table is typically maintained by the wireless service provider of the mobile device through periodic downloads of updated system data. By controlling the contents of the system table, the wireless service provider of the mobile device can establish a priority order among the listed systems that directs the system selection process to its own system and its partner systems.

Conventional mobile devices also include system selection logic that defines a system selection and acquisition procedure. The system selection and acquisition procedures indicate how and when to select systems from the system table, which systems should be given priority, which systems should be avoided, the type of data that should be maintained for each system, and other criteria that affect the order of system selection. In one common system selection and acquisition procedure, the mobile device first steps through a list of systems most recently used by the mobile device, attempting to acquire and log on to each system until a system acquisition and login attempt is successful. If these systems are exhausted without a successful system acquisition, the mobile device attempts to acquire and register with one of the systems listed in the systems table, starting with the most desirable system in the current geographic area and continuing to operate until the least desirable system in the current geographic area. If these acquisition attempts fail, the mobile device scans for available frequencies in an exhaustive search of the local system.

Unlike system tables, which can be easily modified by the wireless service provider, the system selection and acquisition logic that controls when and how systems are selected from the system table is difficult to modify. System selection and acquisition logic for conventional mobile devices is hard coded into the system determination unit circuitry. A proprietary system determination unit may be created if the wireless service provider or mobile device manufacturer is not satisfied with the system selection and acquisition logic in the pre-existing system determination unit. Configuring a system determination unit with unique program logic requires the generation of a corresponding software map that must be tested and loaded into the new system determination unit. This process is expensive, difficult to manage, and time consuming. Additionally, even if the desired system selection and acquisition logic is initially selected for the mobile device, the wireless service provider may later wish to update the system selection and acquisition logic. Changing the system selection and acquisition logic would require replacing the current system determination unit with a new system determination unit that encapsulates the desired program, with the result that such a process, which is often cost-prohibitive and inconvenient to the user, is rarely performed in practice.

To accommodate the specific requirements of different mobile device manufacturers, wireless service providers, and markets, there is a need in the art for efficient and cost-effective methods and apparatus that allow manufacturers and wireless service providers to configure and modify system selection and acquisition logic in mobile devices.

Disclosure of Invention

In a preferred embodiment of the present invention, a mobile station comprises: client circuitry for facilitating wireless communication with a wireless communication system; and a configurable system selection unit that performs a system selection and acquisition procedure. The configurable system selection unit includes: a script engine adapted to execute a working script and a non-volatile memory storing at least one script defining a system selection and retrieval procedure. The system selection and acquisition procedures may be changed by modifying the contents of the non-volatile memory.

In a preferred embodiment, the client circuitry controls operation of the mobile station including facilitating wireless communication with a wireless communication system, and the configurable system selection unit controls system selection and acquisition attempts. The client circuitry may be implemented using conventional circuit elements such as one or more processors, memories, and Application Specific Integrated Circuits (ASICs) as is known in the art.

The configurable system selection unit comprises a front end, a system database and a system selection center. The front end provides an interface between the configurable system selection unit and the client circuitry. The system database stores data describing known wireless communication systems used during system selection and acquisition attempts. The system selection core includes a script table for storing system selection and retrieval logic and a script engine adapted to process the job script.

In a preferred embodiment, the system database comprises: a Preferred Roaming List (PRL), a list of recently used systems, a list of available systems, a list of systems indicating the geographic area of the current serving system, a list of systems that are more preferred than the current serving system, a list of systems that are included in the most recent service redirection message, a list of systems that are currently on a re-acquisition schedule, and a system information table that stores historical information about each system that the configurable system selection unit has attempted to acquire.

Preferably, the front end is adapted to receive a system selection function call from the client circuit and to transmit a corresponding system selection event to the system selection centre. When a system selection function call is received, the front end determines the type of the function call. The system selection function calls may include those function calls that are typically received by system determination units known in the art, and preferably include: user functions, CDMA functions, AMPS functions, HDR functions, GSM functions, WCDMA functions, and other various system selection functions. If the received system selection function call is of a type that can be processed, the front end searches the function call for the received data and, if so, updates the system database. Next, the system selection function call is mapped to a corresponding system selection event. The front end sends the system selection event to the system selection center, and the system selection center processes the event. The front end is further adapted to receive a system selection action from the system selection core and to send a corresponding system selection action to the client circuitry for execution.

When the system selection center receives an event from the front end, the system selection center searches the script table for the received event. In a preferred embodiment, the script table includes a plurality of conditions and corresponding scripts. If a condition evaluates to true, the corresponding script becomes an active script, which is executed by the script engine. If none of the conditions evaluates to true, then the current working script remains in effect. The functionality of each script structure is hard coded into the script engine. The script engine accesses and updates the system database in accordance with the job script and then returns a system selection action to the front end for execution by the client circuitry.

The script table is preferably stored in a non-volatile memory. Where the stored conditions and scripts define the system selection and acquisition procedures used by the mobile station. By changing the stored data, the script table and thus the system selection and acquisition program may be modified. In a preferred embodiment, updates to the script table are downloaded to the mobile station from an external source, such as the mobile station's wireless service provider, via an over-the-air protocol. The invention covers: in alternative embodiments, the script table may be maintained by any entity and may be updated using any data transfer method supported by the mobile station (e.g., data transfer through a serial or USB port using a service programming tool).

A more complete understanding of the method and apparatus for configurable selection and acquisition of a wireless communication system will be afforded to those skilled in the art, as well as a realization of additional advantages and objects thereof, by a consideration of the following detailed description of the preferred embodiment. Reference will be made to the appended figures, which will first be described briefly.

The present application also relates to a configurable system selection unit in a wireless device having client circuitry for controlling operation of the wireless device and facilitating wireless communication with a wireless communication system. The configurable system selection unit includes: a system selection center, the system selection center comprising: a script engine and a random access memory storing at least one script table, the script table including a plurality of system selection event conditions and corresponding scripts defining a system selection and acquisition procedure, the random access memory storing a system database including a list of wireless communication systems; a front end coupled to the client circuitry, the front end adapted to receive system selection function calls from the client circuitry, the front end facilitating communication between the system selection center and the client circuitry, and the front end adapted to convert the received system function calls into system selection events and to transmit the system selection events to the system selection center; wherein the script engine is adapted to detect a system selection event condition and execute the corresponding script, wherein the system selection core is adapted to receive a system selection script and store the received script in the script table, thereby changing the system selection and acquisition procedure, and wherein at least one system selection function call comprises a data parameter and the front end is adapted to update the system database with the received data.

Drawings

The features, objects, and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly throughout and wherein:

FIG. 1 illustrates an operating environment of a mobile station in accordance with a preferred embodiment of the present invention;

fig. 2 illustrates a mobile station in accordance with a preferred embodiment of the present invention;

FIG. 3 is a system database in accordance with a preferred embodiment of the present invention;

FIG. 4a is a system table in accordance with the preferred embodiment of the present invention;

FIG. 4b is an acquisition table in accordance with the preferred embodiment of the present invention;

FIG. 5 illustrates a preferred operation of the front end in the configurable system selection unit;

FIG. 6 illustrates a preferred operation of a system selection center in the configurable system selection unit; and

FIG. 7 provides an example of a script table entry.

Detailed Description

A preferred embodiment of the present invention will now be described with reference to fig. 1. Mobile station 2 operates in a geographic region 4 serviced by at least one base station 6. Each base station 6 is connected to a network 8, the network 8 being part of a larger wireless communication system that supports at least one multiple access wireless communication protocol, such as Code Division Multiple Access (CDMA), wideband CDMA (wcdma), Advanced Mobile Phone Service (AMPS), global system for mobile communications (GSM), General Packet Radio Service (GPRS), or High Data Rate (HDR) technology (e.g., 1xEV technology). The mobile station 2 may be any wireless device (fixed or mobile) suitable for wireless communication with at least one base station 6, such as a cellular telephone, pager, Personal Digital Assistant (PDA), vehicle navigation system, or portable computer.

The mobile station 2 includes client circuitry 10 for controlling the operation of the mobile station 2, including facilitating wireless communication with the base station 6, and a configurable system selection unit 12 for controlling system selection and acquisition. Referring to fig. 2, a preferred embodiment of the client circuit 10 and the configurable system selection unit 12 will now be described. Client circuit 10 includes a communication transceiver 50 coupled to an antenna 52, a control processor 54, a signal processor 56, a searcher 58, and a memory 60. The communication transceiver 50 facilitates the reception and transmission of signals through an antenna 52. The control processor 54 controls the operation of the mobile station 2 in accordance with program logic stored in the memory 60 and is adapted to communicate with the configurable system selection unit 12 as described herein. Preferably, the signal processor 56 is adapted to process digital and analog signals. The searcher 58 is adapted to identify valid signals, such as pilot signals, synchronization channels and paging channels, received by the transceiver 50 through the antenna 52.

The components of the client circuitry 10 are well known in the art and may be implemented in many hardware configurations using conventional circuit elements such as one or more processors, memory, and Application Specific Integrated Circuits (ASICs). The design and implementation of hardware for CDMA acquisition is described, for example, in U.S. patent No. 5,109,390 entitled "DIVERSITYRECEIVER IN A CDMA cell TELEPHONE SYSTEM" (diversity receiver in CDMA CELLULAR TELEPHONE SYSTEM), assigned to the assignee of the present invention, and incorporated herein by reference. It should be understood that: the client circuit 10 shown in fig. 2 is illustrative only, and alternate configurations and additional features are contemplated within the scope and spirit of the present invention. For example, the present invention encompasses: the client circuitry 10 and the mobile station 2 may be adapted for voice communications, high speed data communications, video communications, internet applications such as e-mail and world wide web access, position location (e.g., gpsOne developed by the assignee)^TM) Personal navigation, voice recognition, integrated removable storage, and short-range wireless connectivity to local peripherals and devices. In a preferred embodiment, the client circuitry 10 comprises a mobile station modem chipset developed by the assignee to integrate digital and analog functionality with GPS-based position location.

In a preferred embodiment, the configurable system selection unit 12 includes a front end 100, a system database 102, and a system selection center 104. The front end 100 provides an interface between the configurable system selection unit 12 and the client circuitry 10 and is adapted to update the system database 102 with information received in system selection function calls and to map received system selection function calls into system selection events that can be processed by the system selection centre 104. The system database 102 stores data describing known wireless communication systems used during system selection and acquisition. Preferably, the stored data includes both programmable messages (e.g., PRL) and cumulative messages (e.g., MRU) collected by the mobile station 2 during operation. The system selection core 104 is adapted to process the system selection event received from the front end 100 and instruct the front end 100 to perform the next system selection action (e.g., continue, acquire a system, or request a measurement report) by the client circuitry. The system selection core 104 includes at least one script table 106 for storing system selection and retrieval logic scripts and a script engine 108 for executing the stored scripts.

A preferred embodiment of the system database 102 will now be described with reference to fig. 3. The system database 102 includes volatile and non-volatile random access memory that stores a plurality of tables including a Preferred Roaming List (PRL) 110. Referring to fig. 4a and 4b, PRL110 preferably includes a system table 126 and an acquisition table 128. As illustrated, each record in the system table 126 includes a System Identifier (SID)126a, a Network Identifier (NID)126b, an indication 126c of whether the system is preferred (P/N), an identifier 126d of the geographic area (region) covered by the system, desirability information 126e, and a pointer (AT pointer) 126f to one record in the acquisition table 128. Each wireless communication system listed in the systems table 126 is identified by a unique SID 126a, NID 126b pairing and designated as a preferred system by the P/N126 c that can be used by the mobile station 2 during roaming or as a negative system that should not be used by the mobile device 2 during roaming. In alternative embodiments, other system identifiers, such as unique frequency bands, modes and frequencies, internet protocol version 6(IPV6) addresses, or Public Land Mobile Network (PLMN) identifiers, may be used to identify the wireless communication systems listed in the systems table 126. Preferably, the wireless communication systems are grouped by geographic region 126d and stored in the systems table 126 in an ordered manner from the most desirable system to the least desirable system in each region by utilizing the desirability information 126 e.

The acquisition table 128 includes a list of parameters required for acquiring the wireless communication systems listed in the system table 126. As illustrated, each record in the acquisition table 128 preferably includes a pattern 128a, a band 128b, and a frequency 128 c. Preferably, the system table 126 and acquisition table 128 are periodically updated by an external source, such as the mobile station's wireless service provider, by downloading over a wireless connection or by another data transfer method supported by the mobile station 2. It should be understood that: alternative configurations of PRLs 110, system tables 126 and acquisition tables 128, as well as alternative identification and acquisition parameters, may be used in accordance with the present invention.

Referring again to fig. 3, the preferred system database 102 also includes: a most recently used systems list (MRU)112, a list of available systems 114, a list of systems 116 indicating the geographic area of the currently serving system, a list of systems that are more preferred than the currently serving system 118, a list of systems 120 included in the most recent service redirection message, and a list of systems 122 that are currently on the reacquisition schedule.

The system database 102 also includes a system information table 124 that stores historical information about each system that the configurable system selection unit 12 has attempted to acquire. Preferably, the stored information includes a system identifier, a PRL flag, a roaming status, an identifier of the last system selection event received for the system, a time of receipt of the last system selection event, a last received power or pilot strength measurement, and a schedule indicating when the system should be revisited for reacquisition attempts or when any acquisition attempts should be avoided for the system. In a preferred embodiment, each system is defined as a unique set of modes, frequency bands, and CDMA channels/AMPS systems. In alternative embodiments, other system identifiers may be used, including: a unique SID, NID pair, internet protocol version 6(IPV6) address or a Public Land Mobile Network (PLMN) identifier. The system information table 124 is updated on a regular basis during operation as the configurable system selection unit 12 collects information about the system.

The preferred operation of the front end 100 will now be described with reference to fig. 5. The front end 100 is adapted to receive a system selection function call 130 from the client circuitry 10 and to transmit a corresponding system selection event 132 to the system selection centre 104. When a system selection function call 130 is received, the front end 100 determines the type of function call. The system selection function call may comprise the same function call as is known in the art and is typically received by the system determination unit. In a preferred embodiment, the system selection function call includes a user function 134a, a CDMA function 134b, an AMPS function 134c, an HDR function 134d, and various other system selection functions 134 e. The received user functions 134a are derived from user actions such as: a command to power up the mobile station 2, enter an offline CDMA mode, enter an offline AMPS mode, exit a power-save mode of operation, change system selection preferences, and power down the mobile station 2.

The CDMA functions 134b are specific to the CDMA mode of operation and include CDMA acquisition and operation functions. The CDMA acquisition function may include an indication that CDMA acquisition failed during the pilot channel acquisition or synchronization channel acquisition substates, an indication that CDMA acquisition failed due to protocol mismatch, and an indication that the CDMA synchronization channel message was successfully received and protocol checks are compatible. The CDMA operation function may include an indication that: registration has been rejected, acquired system is lost, redirection to CDMA is received, redirection to AMPS is received, client 10 has accepted/rejected redirection, measured pilot power is below a certain threshold, access attempt has been terminated (e.g., due to rejected access, system lost, maximum access probe, etc.), and other CDMA functions. In the preferred embodiment, the CDMA function 134b is processed only when the client circuit 10 is operating in CDMA mode.

AMPS functions 134c are specific to the AMPS mode of operation and include AMPS acquisition functions and AMPS operating functions such as AMPS rescan and AMPS base station overload. In a preferred embodiment, the AMPS functions 134c are processed only when the client circuit 10 is operating in AMPS mode.

HDR functions 134d are specific to the HDR mode of operation and include functions such as HDR redirection and HDR session close error. In the preferred embodiment, the HDR function 134d is only processed when the client circuit 10 is operating in HDR mode.

Other various functions 134e include other functions such as system selection timer termination and an indication that the mobile station is to enter a power saving mode of operation.

It should be understood that: the functional calls listed above are illustrative only and the set 134 of actual functional calls supported by the client circuitry 10 and the head-end 100 will depend on the particular implementation of the mobile station 2.

If the received system selection function call 130 is of a type that can be processed, the front end 100 searches the function call 130 for the received data and, if so, updates the system database 102 with the updated data 136. Next, the system selection function call 130 is mapped to a corresponding event 132 that may be processed by the system selection center 104. The front end 100 sends a system selection event 132 to the system selection core 104, and the system selection core 104 processes the event 132. The front-end 100 is further adapted to receive a system selection action 140 from the system selection core 104 and to send a corresponding system selection action 142 to the client circuitry 10. The system selection action 142 may include these instructions to the client circuitry 10: continue with current mode of operation, acquire CDMA system, acquire AMPS system, acquire HDR system, request dedicated mode channel strength measurements from searcher 58, request background mode channel strength measurements from searcher 58, enter power save mode of operation, accept mode suggested by base station, band and CDMA channel/AMPS system, release a call, and other actions performed by client circuitry 10.

A preferred operation of the system selection centre 104 will now be described with reference to figure 6. When the system selection core 104 receives an event 132 from the front end 100, the system selection core 104 searches the script table 106 for the received event 132. In a preferred embodiment, the script table 106 includes a plurality of conditions 150 and corresponding scripts 152. The script table 106 is searched (e.g., from top to bottom) until one of the conditions 150 evaluates to true. For example, if a certain user event is received (e.g., the event is user power), the condition may identify a script to be executed. If a condition evaluates to true, the corresponding script 152 becomes the active script 154, which is executed by the script engine 108. If none of the conditions 150 evaluates to true, then the current active script 154 remains active. In an alternative embodiment, the system selection scripts are grouped into a plurality of script tables, each storing scripts related to a different type of event. When an event is received, the system selection core 104 determines the type of event and searches the appropriate script table for the received event. Script table types may include CDMA acquisition, CDMA operation, AMPS acquisition, AMPS operation, HDR acquisition, HDR operation, and various other tables. Other contemplated script table types include internal event scripts that associate scripts with internal system selection center 104 events and call scripts that associate scripts with activation of other scripts. The scripting engine 108 accesses and updates the system database 102 as needed by the job script 154 and returns a system selection action 140 to the front end 100.

Preferably, the script table 106 is stored in a non-volatile memory. The conditions 150 and scripts 152 stored therein define the system selection and acquisition procedures used by the mobile station 2. By changing the stored data, the script table 106 and thus the system selection and acquisition program may be modified. The script table 106 may be updated using any data transfer method supported by the mobile device 2. In a preferred embodiment, the script table 106 updates are downloaded to the mobile station 2 from an external source, such as the mobile device's wireless service provider, in the same manner as the PRL updates are provided to the mobile station 2 (e.g., over the air using data burst messages or other over-the-air delivery methods). In an alternative embodiment, the script (or a subset of the script) is represented as a hard-coded table that is compiled and loaded into the mobile station by other software.

The scripts 152 may use any format, scripting language, and syntax understood by the scripting engine 108. Each script 152 includes at least one script command, the functionality of which is preferably hard-coded into the script engine 108. Scripts 152 may be created to control any aspect of the system selection and acquisition process, including: the order in which the system acquires the attempts, the type of acquisition to be performed, the mode of acquisition attempt, the measurement of received power/pilot strength, reacquiring the system, and avoiding scheduling of the system. In a preferred embodiment, the script commands are implemented using C macros, and may include a command to sort a list of systems according to sort category (e.g., strongest received power measurement or CDMA system before other systems), a command to acquire channel strength measurements for all systems in the identified list, a command to step through the identified list of systems and attempt to acquire the listed systems that meet a certain criterion (e.g., Rx-power measurement greater than a threshold), and a command to instruct the client circuitry to enter power save mode.

Two script examples are shown in FIG. 7. Item 170 includes a script that is executed when a power sequence is detected. First, the list of available systems is cleared, then an attempt is made to acquire the MRU system, then the preferred PRL system is used to finally acquire a system that is allowed to be available from the list of available systems. These acquisition attempts are repeated for 600 seconds or until a system acquisition attempt is successful. Item 172 includes a script that is executed when a CDMA system is lost. First, a re-acquisition of the lost CDMA system is attempted, and if the attempted acquisition fails, future re-acquisition attempts are rescheduled. Then attempts to obtain a system from the GEO list, followed by the MRU list, the PRL list, and finally a system allowed to be available from the list of available systems. These acquisition attempts are repeated for 600 seconds or until a system acquisition attempt is successful.

Having thus described a preferred embodiment of a method and apparatus for configurable selection and acquisition of a wireless communication system, it should be apparent to those skilled in the art that certain advantages of the system have been achieved. It should also be understood that: various modifications, adaptations, and alternative embodiments thereof may be made within the scope and spirit of the present invention.

The scope of the invention is defined by the following claims.

Claims (7)

1. A mobile station, comprising:

a client circuit for facilitating wireless communications; and

a configurable system selection unit, the configurable system selection unit comprising:

a front end coupled to the client circuitry, the front end facilitating communication between the configurable system selection unit and the client circuitry, the client circuitry further adapted to send a system selection function call to the front end; and

a system selection center coupled to said front end, the system selection center comprising a script engine and a memory storing at least one script table comprising a plurality of system selection event conditions and corresponding scripts defining a system selection and acquisition procedure, wherein said front end is adapted to convert a received system selection function call into a system selection event and to transmit the system selection event to said system selection center, the system selection event having a corresponding detectable event condition;

wherein the script engine is adapted to detect an event condition and execute a corresponding script.

2. The mobile station of claim 1, further comprising a system database, and wherein

At least one system selection function call includes a data parameter and the front end is adapted to update the system database with data received via the system selection function call.

3. The mobile station of claim 2, wherein at least one script, when executed, generates a system selection action that provides an instruction to the client circuit.

4. The mobile station of claim 1, wherein the configurable system selection unit is adapted to receive a system selection script and store the received script in the script table, thereby changing the system selection and acquisition procedure.

5. The mobile station of claim 2, wherein the system database includes a preferred roaming list.

6. A configurable system selection unit for use in a wireless device having client circuitry for controlling operation of the wireless device and facilitating wireless communication with a wireless communication system, the configurable system selection unit comprising:

a system selection center, the system selection center comprising: a script engine and a random access memory storing at least one script table, the script table including a plurality of system selection event conditions and corresponding scripts defining a system selection and acquisition procedure, the random access memory storing a system database including a list of wireless communication systems;

a front end coupled to the client circuitry, the front end adapted to receive system selection function calls from the client circuitry, the front end facilitating communication between the system selection center and the client circuitry, and the front end adapted to convert the received system selection function calls into system selection events and to transmit the system selection events to the system selection center;

wherein the script engine is adapted to detect a system selection event condition and execute the corresponding script,

wherein the system selection center is adapted to receive a system selection script and store the received script in the script table, thereby changing the system selection and acquisition program, and

wherein at least one system selection function call comprises a data parameter and the front end is adapted to update the system database with the received data via the system selection function call.

7. The configurable system selection unit of claim 6, wherein at least one script, when executed, generates a system selection action that provides an instruction to the client circuitry.