Agilent Technologies 8922M, S GSM manual Rssi

Models: 8922M S GSM

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Glossary

RPE-LTP

Regular Pulse Excitation Long Term Prediction. A commonly

 

used technique for converting voice from analog to digital form.

 

This is the CODEC that is used by GSM, DCS1800 and

 

PCS1900 systems.

RSSI

Received Signal Strength Indicator. Reception level.

SACCH

There is a spare frame every 12 TCH frames and this is used for

 

the SACCH (Slow Associated Control Channel). On the down-

 

link, the SACCH is used to send slowly but regularly changing

 

control information to the mobile. The up-link carries

 

information about the received signal strength (RXLev) and

 

quality (RXQual)of the TCH and the adjacent cell BCH

 

measurement.

SDCCH

The SDCCH (Stand-alone Dedicated Control Channel) is

 

sometimes configured on a BCH and sometimes on its own

 

physical channel. The SDCCH has a different multiframe

 

structure to the TCH. SDCCH bursts repeat less frequently than

 

one per frame. For this reason, more than 8 SDCCH can share a

 

physical channel. The data rate on a SDCCH is lower than on

 

the TCH. During the call set-up process, there can be a lot of

 

time between the mobile sending a RACH and getting service,

 

to the start of the conversation. During this period, no speech is

 

transmitted (though communication does take place). This

 

transitional time means less of the cells resource are used, the

 

SDCCH improves efficiency and provides a useful holding

 

channel for the mobile until, speech data needs to be

 

exchanged.

SIM

The SIM (Subscriber ID Module) card plugs into every GSM

 

mobile and holds all the unique subscriber information. It also

 

stores dialing lists, network allowable usage etc.

SMSCB

Short Message Service Cell Broadcast. This service is

 

analogous to the Teletext service offered on television. It

 

permits a number of unacknowledged general messages to be

 

broadcast to all mobiles in a particular region.

Speech Coder

An electronic circuit that converts the audio signal into data and

 

minimizes the number of bits needed to represent the audio.

Trigger Delay

The time delay between a valid trigger event and the digital

 

demodulation of the signal, or the delay between the trigger

 

event and the beginning of a measurement.

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Page 369
Image 369
Agilent Technologies 8922M, S GSM manual Rssi