TelecomStudy18

The X2AP protocol is used to handle the UE mobility within E-UTRAN and provides the following functions: ·          Mobility Management ·          Load Management ·          Reporting of General Error Situations ·          Resetting the X2 ·          Setting up the X2 ·          eNB Configuration Update Protocol specification 3GPP TS  36.423  - Evolved Universal Terrestrial Radio Access Network (E-UTRAN); X2 Application Protocol (X2AP)

  The main functions of X2 interface layer 1 are as following: ·          Interface to physical medium; ·          Frame delineation; ·          Line clock extraction capability; ·          Layer 1 alarms extraction and generation; ·          Transmission quality control. Protocol specification 3GPP TS  36.421  - Evolved Universal Terrestrial Radio Access Network (E-UTRAN); X2 layer 1

S1 signalling bearer provides the following functions: ·          Provision of reliable transfer of S1-AP message over S1-MME interface. ·          Provision of networking and routeing function ·          Provision of redundancy in the signalling network ·          Support for flow control and congestion control L2 - Data link layer Support of any suitable data link layer protocol, e.g. PPP, Ethernet IP layer ·          The eNB and MME support IPv6 and/or IPv4 ·          The IP layer of S1-MME only supports point-to-point transmission for delivering S1-AP message. ·          The eNB and MME support the Diffserv Code Point marking Transport layer SCTP is supported as the transport layer ...

the main functions of S1 interface layer 1 are as following: ·          Interface to physical medium; ·          Frame delineation; ·          Line clock extraction capability; ·          Layer 1 alarms extraction and generation; ·          Transmission quality control. Protocol specification 3GPP TS  36.411  - Evolved Universal Terrestrial Radio Access Network (E-UTRAN); S1 layer 1

·          Low Rx level DL& UL, Bad Qual (Interference ) DL & UL, and High TA ·          Drop on LAC boundary. ·          SW congestion ·          Due to TCH Congestion. ·          Hardware issue, Timeslot Faulty, High VSWR, Alarm or Antenna Faulty, mismatch combining. ·          Interference or error on E1. ·          Drop due to radio failure. ·           SD drop due to MS faulty. ·          SD drop due to mismatch Rxlev_access_min value & RACH busy threshold ·          SD drop due to mismatch BA2 list, due to drop occur during HO.

·          The parameters SACCH Multi-Frames and Radio Link Timeout are set to too small values. ·          The parameter RXLEV_ACCESS_MIN is set to a too small value. ·          The parameter RACH Min.Access Level is set to a too small value. ·          The parameters Min DL Power on HO Candidate Cell and Min Access Level Offset are inappropriately set. ·          The length of timer T3103 (this timer is set to wait for a Handover Complete message) is set to a too small value. ·          The length of timer T3109 (this timer is set to wait for a Release Indication message) is set to a too small value. ·          The length of timer T3111 (this timer specifies the connection release delay) is set...

Cell Selection Procedure • First MS powers-on • MS starts measuring received power level from all cells in range • MS calculates average power level received from each cell: • Stored in RXLEV(n) parameter • MS calculates C1 parameter for each cell based on RXLEV(n) • Mobile compares cells which give a positive value of C1 and ‘camps-on’ to the cell with the highest C1 value. On switch-on, an MS periodically measures the received power level on each of the BCCH frequencies of all cells within range. From these periodic measurements the MS calculates the mean received level value from each cell, stored in the parameter RXLEV (n) where n=neighboring cell number. Cell Re-selection – GSM Phase 1 Mobiles For GSM Phase 1 mobiles, cell reselection is achieved by comparing current cell C1 with neighboring C1 cell measurements: • Between cells within a Location Area: C1 (new) > C1 (old)         (for more than 5 seconds) • Bet...