In a hierarchical telecommunications network the backhaul portion of the network comprises the intermediate links between the core network, or backbone, of the network and the small subnetworks at the "edge" of the entire hierarchical network. For example, while cell phones communicating with a single cell tower constitute a local subnetwork, the connection between the cell tower and the rest of the world begins with a backhaul link to the core of the telephone company's network (via a point of presence).
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Visualizing the entire hierarchical network as a human skeleton, the core network would represent the spine, the backhaul links would be the limbs, the edge networks would be the hands and feet, and the individual links within those edge networks would be the fingers and toes.
Other examples include:
The choice of backhaul technology must take account of such parameters as capacity, cost, reach, and the need for such resources as frequency spectrum, optical fiber, wiring, or rights of way. Backhaul technologies include:
Backhaul capacity can also be leased from another network operator, in which case that other network operator generally selects the technology.
As data rates increase, the range of wireless network coverage is reduced, raising investment costs for building infrastructure with access points to cover service areas. Mesh networks are unique enablers that can reduce this cost due to their flexible architecture.
With mesh networking, access points are connected wirelessly and exchange data frames with each other to forward to/from a gateway point. Since a mesh requires no costly cable constructions for its backhaul network, it reduces total investment cost. Mesh technology’s capabilities can boost extending coverage of service areas easily and flexibly.
For further cost reduction, a large-scale mesh is desirable. To meet this challenge, a high capacity mesh is necessary.
Kyushu University's Mimo-Mesh Project, based in Fukuoka City, Fukuoka Prefecture, Japan, has developed and put into use new technology for building high capacity mesh infrastructure.[1] A key component is called IPT, Intermittent Periodic Transmit. IPT is a proprietary packet-forwarding scheme that is designed to reduce radio interference in the forwarding path of mesh networks.
In 2010, hundreds of wireless LAN access points incorporating the technology were installed in the commercial shopping and entertainment complex, Canal City Hakata, resulting in the successful operation of one of the world's largest indoor wireless multi-hop backhauls.
The wireless network deploying over 200 access point devices built inside Canal City Hakata realizes a wireless multi-hop relay of up to 11 access points while delivering high bandwidth to end users. Actual throughput is double that of standard mesh network systems using conventional packet forwarding.