Enhanced radio resource management algorithms for efficient MBMS service provision in UTRAN
As currently specified by 3GPP, Multimedia Broadcast Multicast Service (MBMS) bearer services can be provided within a cell either by Point-to-Point (P-t-P) or Point-to-Multipoint (P-t-M) transmission mode, but not both at the same time. If P-t-P transmission mode is selected for a cell, one Dedicated Channel (DCH) is established for each user within the cell that joined the MBMS service. Otherwise, if P-t-M transmission mode is selected, one Forward Access Channel (FACH) is established covering the whole cells area and commonly shared by all the UEs within. In this paper, we highlight the inefficiencies that can be caused with the aforementioned approach and introduce the Dual Transmission mode cell in which P-t-P and P-t-M transmissions (i.e. multiple DCHs and FACH) are allowed to coexist within the same cell. Hence, we propose a new radio resource allocation algorithm and solution to address them. Our proposed algorithm considers the instantaneous distribution and movement of the users within the cell and dynamically decides which users will use FACH and which DCH, in such a way that the requested Quality of Service (QoS) is supported with the least amount of transmission power (i.e. capacity) consumption. Moreover, with the Dual Transmission mode cell, new types of intra-cell handovers are introduced which we also analyse and propose a new handover algorithm to address them. The performance evaluation carried out showed that our proposed Dual Transmission mode cell approach, provides considerable gains, as well as outperforming all other related approaches, such as UE Counting, Power Counting, Rate Splitting, and FACH with dynamic power setting, in terms of capacity and link performance efficiency.
3gpp 3rd generation partnership project ah activation hysteresis ar alteration rate ccit cell context information table cn core network cpich common pilot channel dch dedicated channel fach forward access channel fach_it fach information table haa handover activation area hat handover activation threshold hi_table handover information table hsdpa high speed downlink packet access htt handover trigger threshold imsi international mobile subscriber identity mbms multimedia broadcast multicast service mcch mbms point-to-multipoint control channel md mobile device nbap node-b application protocol pp pre-trigger predictor p-t-m point-to-multipoint p-t-p point-to-point qos quality of service rnc radio network controller rrc radio resource control rrm radio resource management sm safety margin tmgi temporary mobile group identity tti transmission time interval ue user equipment umts universal mobile telecommunications system utran umts terrestrial radio access network ?t handover delay time