Dedicated Control Channel (DCCH) in GSM

SDCCH (Stand-alone Dedicated Control Channel) Uplink and Downlink. Used for call setup, authentication, ciphering location update and SMS. SACCH (Slow Associated Control Channel) Downlink and Uplink. Used to transfer signal…

BCH ,CBCH and CCCH works in GSM

Broadcast Channels (BCH) Frequency correction channel (FCCH) the “lighthouse” of a BTS Synchronization channel (SCH) PLMN/base identifier of a BTS plus synchronization information (frame number)  Broadcast control channel (BCCH) to…

BCH,CCCH and DCCH Channel of GSM

BCH (Broadcast Channels) BCCH(Broadcast Control Channels) Downlink Only. Broadcast information of the serving cell (System Information). Transmitted on timeslot zero of BCCH carrier. Read only by idle mobile at least…

Structure of Combined BCCH in GSM

It is used in the configuration of cells of low traffic density and small capacity. The Combined BCCH is only configured at timeslot 0. Channel combination: FCCH?SCH?BCCH?CCCH+SDCCH/4+SACCH/4 SDCCH/4: Stand-alone dedicated…

Uplink Logical Channel in GSM

1. Random access channel (RACH) It is an uplink channel used for MS randomly access to network by requesting for an SDCCH. The request includes a 3bit setup reason (call…

How 26 and 51 Multiframes in GSM

GSM is very complicated when we talk about its rf side and in it very complicated to understand the structure of 26 and 51 Multiframes, here my try to make…

What is Frequency Hopping in GSM

When using close frequency reuse technique, system interference is the most important factor for frequency reuse ratio. Usually, power control and discontinuous transmission technologies are adopted to lower system interference.…

Hopping Effect in Cell Coverage area and on Mobile Speed

Effect in Cell Coverage Area In coverage limited cells the frequency hopping may increase the cell coverage area because of the frequency diversity gain, but since the BCCH time slot…

How Different Frequency Diversity gains with Cyclic and Random Hopping

Cyclic vs. Random Hopping Sequences Both cyclic and random hopping modes are available in GSM. In the cyclic mode the frequencies are changed sequentially from the lowest frequency to the…