Cellular Phone: Description and Operation

CELLULAR SYSTEM PERFORMANCE INFORMATION
Most complaints relating to the performance of the cellular telephone are not due to a malfunction of the Lexus Telephone Network itself. It is more likely that the cause lies in the characteristics inherent to wireless communications.
Radio signals both transmitted and received by the cellular telephone work best when there is an unobstructed path between the vehicle's antenna and the network's "base site" antennas.
Because of the reflecting characteristics of the cellular phone radio signal, directed and reflected signals may reach the antenna at the same time. ("multipath"). They cancel each other out creating small "islands" where audio "nulls" occur. As the car moves through these spots, the caller will hear a momentary flutter. This same characteristic causes "ghost" images in television when an airplane flies over.
Multipath can also cause a "cross-talk" phenomenon, where the driver may temporarily hear another cellular conversation.
Other common symptoms which may occur in a cellular conversation are:

Symptom - Cause
Static - Lack of coverage or Multi-path" condition.
Crosstalk - The cellular telephone has captured a "voice channel" from another base site due to weak coverage or multi-path condition. This is a landline or system coverage problem.
Dropped calls - Weak coverage area, multi-path condition or "system" drop.
Clicks/occasional chopped word. - System handoff to another base site.
Increased/decreased volume at either landline or vehicle Echo or feedback. - The current "Voice channel" that the system has assigned to the cellular telephone has a higher or lower gain or more or less "sidetone" compared to a previous channel.

ADDITIONAL SYSTEM COVERAGE TIPS
1. Each cellular system provides unique geographical coverage patterns which have weak signal areas within its boundaries due to topography, man-made structures. etc. Thus, sometimes switching a customer over to the other cellular system provider can make sense in providing better coverage for a customer's particular phone use area.
2. Enlist the customer's help in providing cellular system coverage troubleshooting information. Use of the signal strength meter can help provide the information regarding strength of the system coverage where problematic conditions occur.

SPECIFIC PORTABLE COVERAGE TIPS
The portable is more likely to be affected by the strength of the cellular system coverage since it can be carried into more problematic locations (i.e. buildings) and since its output power is lower than the mobile. The antenna is designed for optional performance with the antenna extended. The customer should extend the antenna especially if the following occurs:
(a) Signal strength meter shows low signal strength.
(b) NS (no service) lights flashes or lights steadily.
(c) Weak signal alert is indicated. (series of beeps, call appears in display)