Patent ID: 7471713

Claim:
A method for reassigning codes of an orthogonal variable spreading factor code tree in code division multiple access communications to a new call, the code tree having a plurality of codes at differing spreading factors and having a plurality of branches between the codes of different spreading factors, if a particular code of the code tree is assigned, a lower spreading factor code of the code tree connected to that code by one of the branches is blocked from assignment, if a code of the code tree is blocked, a code of the tree of a lower spreading factor connected to that code by one of the branches is blocked from assignment, the method comprising: finding a code of a highest spreading factor in a time slot; determining if a leftward code of the highest spreading factor code in the time slot is available; relocating the new call into the leftmost available code in the time slot; and repeating, for a next lower spreading factor, finding a code of the next lower spreading factor in the time slot, determining if a leftward code is available in the time slot, and relocating the new call to the leftward available code.