Methods and apparatuses for handling data traffic in a radio node having a split protocol stack

Abstract

In one aspect of the teachings herein, a radio node provides a local loopback mode of operation in at least some operational instances, in which it loops 'local' traffic between wireless devices operating within a local radio cell or cells, rather than forwarding such traffic along to a controlling gateway for handling. The wireless devices operating within the cell(s) and involved in the loopback operation switch over from symmetric encryption that involves the controlling gateway as a secure endpoint for their traffic, to asymmetric or public-private key pair encryption. The radio node uses a correspondingly derived loopback encryption key to enable security on the loopback traffic flow between the involved local devices. Use of the loopback encryption key means that the radio node need not know or otherwise have access to the symmetric encryption keys used by the involved devices and the controlling gateway for 'normal' non-loopback operation.