Concept of Flexible Abis is in fact an Abis pool for one TG. One TG corresponds to one E1 and can be used by multiple synchronized cells. Purpose is to make a pool for E-PDCHs and G-PDCHs. Any cell can used a 16K or 64K TS from the pool whenever needed i.e. saving Abis by trunking.
Ericsson claims that it saves almost 35% Abis resources with less than 15% loss in EDGE performance where usage of EDGE is 15-20%.
By flexible Abis in Ericsson can save efficeintly the bandwidth and GSL devices .
good point from optimization point of view is that if we have more number of users in once cell in a site and less in ohter cell in the same site no need to upgrade the the E1 or incrased the capacity the EDGE /GPRS all the cells which are conneted to the one site will feed the amount Data traffic from same pool .