E

ESN - Electronic Serial Number.

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.