Patent ID: 8934438
Filing Date: 2015-01-13
Classification: H04W

Abstract:
1. A method comprising: a) receiving, by a wireless device configured to communicate employing a plurality of cells, at least one control message from a base station, said at least one control message causing in said wireless device: b) generating a first updated timing advance by updating a first timing advance of said secondary cell group, by said wireless device, employing at least one first timing advance command for said secondary cell group; c) storing, by said wireless device, said first updated timing advance upon expiry of an associated time alignment timer of said secondary cell group; d) receiving, by said wireless device, a second timing advance command for said secondary cell group with a timing advance value of zero, said second timing advance command starting said associated time alignment timer; e) receiving, by said wireless device, an uplink grant for an activated cell of said secondary cell group; and f) transmitting, by said wireless device, uplink signals in radio resources identified in said uplink grant with a timing advance equal to said stored first updated timing advance.