CHANNEL ELEMENT (CE) DIMENSIONING . capacity of a sector is calculated by the number of available TCH timeslots.2G and 3G COMPARISON: • in 2g systems. 4 kbps Control Channels CEs Required 1 2 4 8 16 32 1 16 . capacity of sector is calculated by the number of available CE. Services PS: 8 kbps.… continuation: * in 3G systems.2 kbps AMR PS: 32 kbps PS: 64kbps. 128 kbps (including ADCH) CS: 64 kbps PS: 256 kbps PS: 384 kbps (including ADCH) HSDPA scheduler reserved blocks for 5 codes (UL and DL) HSDPA UL SRB: 3. Utilization of CE varies for different traffic classes / bearers / services. 16 kbps CS: 12. and is dependent on the radio bearers to be used. as well as on the number of simultaneous users for each specific radio bearer. required in a RBS is based on the traffic type. NCE. .DEFINITION: • describes the SW licensed capacity resources required for a dedicated channel (DCH or E-DCH). • the number of channel elements. channel elements will be consumed in UL and DL. • the consumption can be described as a cost. blocking might occur. • if there is an insufficient amount of channel elements available. To avoid blocking. .HARDWARE: • each time a dedicated channel is allocated. and depends on the type of radio bearer for the dedicated channel. a best effort user will be switched down to a lower rate to make channel elements available for the requested dedicated channel. and consider which among the UL and DL CE requirements is higher. Thus the CE requirements for the Node B must be computed separately for UL and DL using the individual service bit rates. which means that the CEs are allocated separately in uplink and downlink.…continuation: • channel elements are asymmetrically allocated. aside from the 32 CEs reserved for HSDSCH downlink traffic. the corresponding A-DCH (Associated DCH) on uplink and SRB (Signaling Radio Bearer) on downlink must be considered. • for HSDPA. . … continuation: * for UL A-DCH the channel elements needed is based on the bearer rate. . while for DL SRB only one CE is used in each connection. CS64.INPUTS REQUIRED: • number of subscribers per Node B • traffic usage per subscriber per application: AMR. PS128. HSDPA or • traffic usage per application . PS384. PS64. ASSUMPTIONS: * Soft Handover Overhead (SHO) = 30% . DIMENSIONING PROCESS: • compute separately for UL and DL CE Requirements • determine the total traffic per application per Node B • compute the number of CEs required per application (R99 CE) • compute CEs needed by A-DCH based on HSDPA bearer rate for UL and 1 CE on each connection for DL • add the CEs required for R99 and HSDPA A-DCH . SHO. use the higher value to compute the number of modules required: eg.… continuation: • compute for the Soft Handover CE Requirement by multiplying the above result by SHO • add the CEs for HSDPA scheduler reserved block • add the CEs needed for control channels • sum up the CEs required for R99 and A-DCH. HSDPA scheduler and control channels to get the total required CEs for UL and DL • compare the DL and UL CE requirements. 1 module = 192 CEs . 5 x 64/128 PS. 2 x 384/HSPDA • SHO = 30% • Max 16 HSDPA users per BTS Compute for the DL and UL CE Requirements . 2 x 64/384 PS.EXAMPLE: • Node B with 3 sectors • BH Traffic mix: 12 x AMR. 3 x CS64. … continuation: Number of users 12 3 5 2 2 R99 and ADCH Reqt SHO Requirements HSDPA scheduler Control Channels Total CEs Required Services 12.3= 26 32 16 158 DL CE Requirement 12*1 = 12 3*4 = 12 5*4 = 20 2*16 = 32 2*1 = 2 78 78*0.2 kbps AMR CS 64 kbps PS 64/128 kbps PS 64/384 kbps 384 A-DCH HSDPA UL CE Requirement 12*1 = 12 3*4 = 12 5*4 = 20 2*4 = 8 2*16 = 32 84 84*0.82 = 1 module .3 = 24 32 16 150 Module Required =158/192 = 0.