CellSlice: Cellular wireless resource slicing for active RAN sharing

We present the design and implementation of Cell-Slice, a novel system for slicing wireless resources in a cellular network for effective Radio Access Network (RAN) sharing. CellSlice is a gateway-level solution that achieves the slicing without modifying the basestations' MAC schedulers, thereby significantly reducing the barrier for its adoption. Achieving slicing with a gateway-level solution is challenging, however, since resource scheduling decisions occur at the basestations at fine timescales, and these decisions are not visible at the gateways. In the uplink direction, CellSlice overcomes the challenge by indirectly constraining the uplink scheduler's decisions using a simple feedback-based adaptation algorithm. For downlink, we build on the technique used by NVS, a native basestation virtualization solution, and show that effective downlink slicing can be easily achieved without modifying basestation schedulers. We instantiate a prototype of CellSlice on a Picochip WiMAX testbed. Through both prototype evaluation and simulations, we demonstrate that CellSlice's performance for both remote uplink and remote downlink slicing is close to that of NVS. CellSlice's design is access-technology independent, and hence can be equally applicable to LTE, LTE-Advanced and WiMAX networks.