  Explosion of mobile traffic will bring a heavy burden to the core network,
and rapid growth of mobile devices, as well as increasing demand for
delay-sensitive services poses severe challenges to future wireless
communication systems. In this regard, local breakout is a promising solution
to save core network load and, more importantly, to reduce end-to-end (e2e)
delay of packets with local significance. However, the capacity of local
breakout link is limited, resulting in excessive delay when the traffic load
through the local link is high. Therefore, the decision on whether the traffic
flows should be transmitted through core network or by local breakout link has
great practical significance. In this paper, we propose and implement a novel
local breakout framework to deliver low e2e delay packets with local
significance. A real-time local breakout rule based on the solution to a Markov
decision process is given, showing that some packets with local significance
should pass through core network rather than being delivered by local breakout
link to meet the delay requirements. To test our proposed framework, a
long-term-evolution (LTE) based test-bed with virtual base stations is
implemented, by which we show the proposed framework is feasible and the e2e
delay is significantly reduced.
