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Timing Advance in GSM

Timing Advance in GSM Transmission delay is unavoidable in the radio interface. If the mobile station moves away from the base station during a call, the further distance the more delay. The uplink is as the same. If the delay is too high, the timeslots of the signal from a certain mobile station and that … Read more

BCH,CCCH and DCCH Channel of GSM

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 once every 30 secs. SCH (Synchronization Channels) Downlink Only Carries information for frame synchronization. Contains frame number and BSIC … Read more

Dedicated Control Channel (DCCH) in GSM

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 while MS have ongoing conversation on traffic or while SDCCH is being used. On the forward link, the SACCH … Read more

Timing Advance in LTE

Timing advance lte what is timing advance in lte: -The eNB measures the required timing advance based on the received UE signal arrival time. It commands the UE to adjust the transmission time. This is performed on a per-need basis. It is signaled by means of a special MAC control element; LCID = 11101. The … Read more

DL scheduler in LTE

The DL scheduler is spit into 3 functional parts: 1.The Static Scheduler: Which assigns a fixed amount of Transport Blocks as well as PDCCH and PDSCH resources for the BCCH over the DL-SCH Transport Channel.Those resources are permanently allocated. 2.The Semi-static Scheduler: Which assigns Transport Blocks as well as PDCCH and PDSCH resources for PCCH … Read more

Non-contention vs Contention Access procedure in LTE

Random access procedure is performed for the following five events: • Initial access from RRC_IDLE; • RRC Connection Re-establishment procedure; • Handover; • DL data arrival during RRC_CONNECTED requiring random access procedure; • UL data arrival during RRC_CONNECTED requiring random access procedure; E.g. when UL synchronization status is “non-synchronized” or there are no PUCCH resources for … Read more