  Network coding is an effective idea to boost the capacity of wireless
networks, and a variety of studies have explored its advantages in different
scenarios. However, there is not much analytical study on throughput and
end-to-end delay of network coding in multi-hop wireless networks considering
the specifications of IEEE 802.11 Distributed Coordination Function. In this
paper, we utilize queuing theory to propose an analytical framework for
bidirectional unicast flows in multi-hop wireless mesh networks. We study the
throughput and end-to-end delay of inter-flow network coding under the IEEE
802.11 standard with CSMA/CA random access and exponential back-off time
considering clock freezing and virtual carrier sensing, and formulate several
parameters such as the probability of successful transmission in terms of bit
error rate and collision probability, waiting time of packets at nodes, and
retransmission mechanism. Our model uses a multi-class queuing network with
stable queues, where coded packets have a non-preemptive higher priority over
native packets, and forwarding of native packets is not delayed if no coding
opportunities are available. Finally, we use computer simulations to verify the
accuracy of our analytical model.
