Patent ID: 8214470

Claim:
A method of operating a flat radio access network comprising plural radio base stations, the method comprising: grouping the plural radio base stations into clusters, each of the plural radio base stations being connected without an intervening superior radio access node to a core network; designating a master radio base station for a cluster, wherein the master radio base station is one of the plural radio base stations in the cluster; using the master radio base station to initiate a parallel software upgrade of the radio base stations in the cluster; using the master radio base station to perform a monitoring of implementation of the parallel software upgrade at the radio base stations of the cluster, and on the basis of the monitoring, determining whether the parallel software upgrade is successful; and using the master radio base station to initiate an upgrade rollback when the master radio base station determines that the parallel software upgrade is not successful; using the master radio base station to issue different priority alarms to an operation support entity if the parallel software upgrade is not successful and the upgrade rollback is not possible related to a network problem or the software upgrade was faulty.