  In edge computing (EC), by offloading tasks to edge server or remote cloud,
the system performance can be improved greatly. However, since the traffic
distribution in EC is heterogeneous and dynamic, it is difficult for an
individual edge server to provide satisfactory computation service anytime and
anywhere. This issue motivated the researchers to study the cooperation between
edge servers. The previous server cooperation algorithms have disadvantages
since the cooperated region is limited within one-hop. However, the performance
of EC can be improved further by releasing the restriction of cooperation
region. Even some works have extended the cooperated region to multi-hops, they
fail to support the task offloading which is one of the core issues of edge
computing. Therefore, we propose a new decentralized and borderless server
cooperation algorithm for edge computing which takes task offloading strategy
into account, named CoNet. In CoNet, the cooperation region is not limited.
Each server forms its own basic cooperation unit (BCU) and calculates its
announced capability based on BCU. The server's capability, the processing
delay, the task and calculation result forwarding delay are considered during
the calculation. The task division strategy bases on the real capability of
host-server and the announced capability of cooperation-servers. This
cooperation process is recursive and will be terminated once the terminal
condition is satisfied. The simulation results demonstrate the advantages of
CoNet over previous works.
