E- Glossary

EIA/TIA-553 - The ANSI version of the analog cellular standard. Generally one step behind IS-91, and without support for NAMPS.
Electronic Serial Number (ESN) - A 32 bit code that is unique to each mobile unit. Used to validate mobile. Not alterable by both cellular operator and end user. Each cellular phone is assigned an ESN, which is automatically transmitted to the base station every time a cellular call is placed. The Mobile Telephone Switching Office checks the ESN to make sure it is valid, that the phone has not been reported stolen, that the user's monthly bill has been paid, etc., before permitting the call to go through.
Erlang - A dimensionless quantity used in the traffic statistical measurements in the cellular system. One erlang is equivalent to the average number of simultaneous calls. One erlang equals 3600 call-seconds per hour or 36 CCS (call century seconds) per hour.
ESMR - Enhanced Specialized Mobile Radio. Digital mobile telephone services offered to the public over channels previously used only for analog two-way dispatch.
ETACS - Extended TDMA. This system uses the same 30 KHz channels as TDMA, but has six users per channel. The vocoder rate is cut to 4 Kbits/sec, and the channels are dynamically assigned based on voice activity detection.
ETSI - European Telecommunications Standards Institute. The mission of ETSI is "to produce the technical standards which are necessary to achieve a large unified European telecommunications market". This includes the specification of the GSM cellular and PCS standard.
Execute source - An order sent to the mobile on the Forward Voice Channel telling mobile to change channels. Order contains new channel number and new power level.
Execute target - An order sent to the cell a mobile is being handed off to, informing the cell of the pending arrival of a mobile.