Cellular Phone: Description and Operation

ONSTAR DESCRIPTION AND OPERATION

This vehicle uses the F1 version of the OnStar(R) system. This system consists of the following components:
^ Vehicle Communication Interface Module (VCIM)
^ OnStar(R) button assembly
^ Microphone
^ Cellular antenna
^ Navigation antenna

This system also interfaces with the factory installed vehicle audio system.

Vehicle Communication Interface Module (VCIM)
The VCIM is a 3-watt cellular device that allows the user to communicate data and voice signals over the national cellular network. It is powered by a fused, battery positive voltage circuit, connected through vehicle wiring to the 3-button assembly and the radio, and attached by means of coax cables to the cellular and navigation antennas. Ground for the module is accomplished by means of dedicated circuits that are routed with body wiring systems to chassis ground points. The module houses two modems, one to process GPS data, and the other for cellular information. Satellites orbiting earth are constantly transmitting signals of their current location, from which the OnStar(R) system is able to pinpoint its own location. The navigation antenna receives these GPS signals and provides the data to the VCIM to be processed. The Vehicle Communication Interface Module communicates with the rest of the vehicle over the class 2 serial data bus. Ignition state is determined by the VCIM through class 2 messaging. The module also has the capability of commanding the horn, door lock/unlock and operating the exterior lamps using the class 2 serial data circuit. When an OnStar(R) keypress is made, a class 2 message is sent to the audio system to mute all radio functions and transmit OnStar(R) originated audio. After the audio system is muted, the OnStar(R) signals are transmitted to the audio system on the cellular telephone voice signal circuit, and returned to the module on the cellular telephone voice low reference circuit. The cellular modem connects the OnStar(R) system to the cellular carrier's communication system by interacting with the national cellular infrastructure. The module sends and receives all cellular communications over the cellular antenna and cellular antenna coax.

OnStar(R) Button Assembly
The OnStar(R) button assembly may be part of the rear view mirror on some vehicles and a separate unit on others. The button assembly is comprised of the three buttons and a status LED. The buttons are defined as follows:
^ The Answer/End Call button, which is black with a white "dot", allows the user to answer and end calls or initiate the personal calling feature if equipped.
^ The blue OnStar(R) Call Center button, which displays the OnStar(R) logo, allows the user to connect to the OnStar(R) Call Center.
^ The red Emergency button sends a high priority emergency call to the OnStar(R) Call Center when pressed.

The OnStar(R) button assembly receives ten volts on the keypad supply voltage circuit. When pressed, each button completes a circuit across a resister allowing a specific voltage to be returned to the VCIM on the keypad signal circuit. Depending upon the voltage range returned, the VCIM is able to identify which button has been pressed.

The OnStar(R) button assembly status LED is green when the system is on and operating normally. When the status LED is green and flashing, it is an indication that a call is in progress. When the LED is red, this indicates a system malfunction is present. The OnStar(R) LED is controlled by the VCIM over the keypad red LED signal circuit and the keypad green LED signal circuit.

OnStar(R) Microphone
The OnStar(R), or cellular, microphone can be part of the rear view mirror assembly or, on some vehicle lines, can be a separate, stand-alone unit. In either case, the microphone is supplied voltage on the cellular microphone signal circuit, while voice data from the user is sent back to the VCIM by means of either a cellular microphone low reference circuit or a drain wire.

Cellular and Navigation Antennas
The cellular antenna is the component that allows the OnStar(R) system to send and receive data over airwaves by means of cellular technology. This antenna is connected at the base to a coax cable that plugs directly into the Vehicle Communication Interface Module. The navigation antenna is used to collect the constant signals of the orbiting satellites. Within the antenna, is housed a "low noise" amplifier that allows for a more broad and precise reception of this data. Current GPS location is collected by the module every time a keypress is made. The OnStar(R) Call Center also has the capability of "pinging" the vehicle during an OnStar(R) call, which commands the module to retrieve the latest GPS location and transmit it to the OnStar(R) Call Center. A history location of the last recorded position of the vehicle is stored in the module and marked as "aged". In the event the VCP loses or is removed from power, this history location is used by the OnStar(R) Call Center as a default. Actual GPS location may take up to 10 minutes to register in the event of a loss of power. This antenna requires a clear and unobstructed path to the satellites in the sky. Window tinting on vehicles may interfere with the GPS sensor functions, depending upon the amount of darkening and/or metallic particles that are embedded in the film of the tinting material.

OnStar(R) Reconfiguration Procedure
Within the Vehicle Communication Interface Module are a set of unique numbers that identify the OnStar(R) customer and the specific vehicle the module resides in. These numbers, the Station Identification Number (STID) and the Electronic Serial Number (ESN) are transmitted over the cellular network when an OnStar(R) keypress is made and are essential for proper identification and connection to the OnStar(R) Call Center. In the event the VCIM requires replacement, the OnStar(R) Reconfiguration procedure must be performed. This procedure allows for the new STID and ESN within the replacement module to overwrite the old numbers and update customer and vehicle information at the OnStar(R) Call Center. The Reconfiguration process is explained within the Vehicle Communication Interface Module replacement procedure.

OnStar(R) Cellular, GPS, and Diagnostic Limitations
The proper operation of the OnStar(R) System is dependent on several elements outside the components integrated into the vehicle. These include the National Cellular Network Infrastructure, the cellular telephone carriers within the network, and the Global Positioning Satellite system.

The cellular operation of the OnStar(R) system may be inhibited by factors such as the user's range from an analog cellular tower, the state of the cellular carriers' equipment, and the location where the call is placed. Making an OnStar(R) keypress in areas that lack sufficient cellular coverage or have a temporary equipment failure will result in either the inability of a call to complete with a data transfer or the complete inability to connect to the OnStar(R) Call Center. The OnStar(R) system may also experience connection issues if the identification numbers for the module (STID and ESN numbers) are not recognized by the cellular carriers local signal receiving towers. OnStar(R) cellular connection issues such as these require the assistance of the General Motors Technical Assistance Center OnStar(R) Group, which coordinate with cellular carriers to resolve connection issues.

The satellites that orbit earth providing the OnStar(R) system with GPS data have nearly no failures associated with them. In the event of a no GPS concern, the failure will likely lie with the inability of the system to gain GPS signals because of its location (i.e. in a parking structure), hardware failure, or being mistaken with an OnStar(R) call which has reached the Call Center without vehicle data. During diagnostic testing of the OnStar(R) system, the technician should ensure the vehicle is located in an area that has a clear unobstructed view of the open sky, and preferably, an area where analog, cellular calls have been successfully placed. These areas can be found by successfully making an OnStar(R) keypress in a known good OnStar(R) equipped vehicle and confirming success with the OnStar(R) Call Center advisor. Such places can be used as a permanent reference for future OnStar(R) testing.

Operation of the Hands Free Cellular Phone

Dialing A Phone Number Hands Free:

The hands free, personal calling cellular phone feature is an additional option to the OnStar(R) system. During a hands free call, the microphone and audio system operate the same way as a standard OnStar(R) call. When the answer/end call button is pressed, the audio system will mute, the OnStar(R) system will then return the prompt "ready". At this point there are specific commands set to initiate a cellular call. If the vehicle receives a call when the radio is on, the audio system will mute and an audible "ring" will be heard though the speakers. The call will be answered when the answer/end call button is pressed. All the voice activated commands are interpreted by the Vehicle Communication Interface Module. A list of these commands is supplied in the information provided to the customer. If the information is not available to reference, at any command prompt the caller can say "HELP" and the VCIM will return an audible list of available commands. If the customer concern is not being understood or not being heard by the OnStar(R) system, the user should place a call to the OnStar(R) call center to verify proper operation of the microphone. Here is an example of the commands and the OnStar(R) system responses. A complete list of commands is supplied in the information provided to the customer with the OnStar(R) system.

Operation of the OnStar(R) Speech Recognition Systems

General Tips For Better Speech Recognition Part 1:

General Tips For Better Speech Recognition Part 2:

Personal Calling Commands Part 1:

Personal Calling Commands Part 2:

OnStar(R) Gen F1 users communicate with two speech recognition systems. Speech recognition allows the user to speak to one computer in the vehicle, and one reached over a phone line. The computer tries to understand the user's command, and responds by speaking back, or by taking the appropriate action, e.g. dialing the phone.
1. Personal Calling uses a speech recognition system that resides in the vehicle. When the user presses the dot button, the system states, "Ready", and listens for the user's command. The user can speak commands to control the hands-free phone.
2. Virtual Advisor is a remote speech recognition system that the caller access by making a phone call. The user connects to Virtual Advisor by requesting it during personal calling use. The user is then transferred to the Virtual Advisor server and talks to it via a cellular connection.

The OnStar(R) speech recognition systems use speech technology that is designed to understand a wide range of American English speakers. Although there is no one "right" way to speak English, the system will work best when users try to modify their pronunciation should they encounter difficulty. Users who do not obtain good results are advised to try the tips and "workarounds" found.