..::difficulty in CDMA::..

Yah first word after a lot of problem in our network..major issued in [W]CDMA network is: limited capacity by power, Walsh code, Traffic Channel Element, Overshooting sector that will make quality decreasing and etc
may be i will break down case by case and give a recommend what we can do to solve [in my experiences]

• Capacity limited by Power

In [W]CDMA system power is main issued of capacity, a lot of user access the network will make Ec/Io increasing, like show in a picture

too many user access the sources will make power closed to threshold. what we can make to increase capacity that caused by power limited. first of all we can increase transmit power [carrier power/cell power] that will make another space to user for access the traffic channel, increasing transmit power must balanced with limited the coverage too, cause it higher transmit power will make another neighbor cell will polluted, or we can decrease DGU [Data Gain Unit] or usually we said pilot, sync and paging, to make more spare for user. usually this case happen in urban city, cause a lot of user access Data and Voices in one time. another case is capacity limited by TCHe and Walsh Code, below is my recommend for increasing capacity will put in another point

• Capacity Limited by Walsh Code

below is a simple picture of Walsh Code Tree
in [W]CDMA system Walsh code tree 0 [W0] is used by Pilot to send user a parameter that used in [W]CDMA system like NL [Neigbor List], and etc, Walsh Code tree 1 [W1] is used for paging slot, LAC, P_REV, MIN_P_REV, T_ADD, T_DROP, T_COMP, T_TDROP is send from this slot, and Walsh Code 31 [W31] is used for sync slot.
Walsh code tree in CDMA usually use Walsh Code 64 [Vendor and Customer Agreement and specification] increase Walshcode tree will increasing Traffic Channel Element [TCHe] too, cause there are will increase and make spare for user used the sources of CDMA network.

so now we have increase more transmit power [carrier/cell power] and if still have a problem with limited capacity, we check a walsh code occupancy, if walsh code limited too, so we increase the length of walsh code. if still have a problem with a capacity again, please check how much percentage of Soft Handoff [SHO] in that site, if SHA larger than 40%, we must decrease SHO, how to decrease SHO in our network? i will write again tomorrow in another topic.