Look through multiple summaries of the use and topology of Carrier Ethernet, in these graphics from CE provider RAD Data Communications. Learn more here about details on the ways Carrier Ethernet can be used for wholesale backhaul, small cell backhaul, and Ethernet over TDM.
This slide looks at some of the elements a wholesale backhaul provider can utilize for a pure Ethernet backhaul network, according to Eitan Schwartz, vice president of Carrier Ethernet of RAD Data Communications’ U.S. operations. Demarcation devices must be selected for the cell sites and switching centers, and those devices should be simply configured and managed.
According to Schwartz: “Since port costs on a typical provider edge switch are very high, it may also make sense to utilize much lower cost access aggregation devices that are scalable and can slash your port costs by at least 2/3rd  They should also support both hub and spoke as well as ring topologies.”
Schwartz: “Wholesale backhaul is being driven by the need for scalable Ethernet pipes to carry 3G and 4G packet-based traffic, however most cell sites still support 2G/3G traffic that is carried over traditional T1/E1Â leased lines. To reduce the expense of maintaining dual network infrastructures it typically makes sense to consolidate TDM and Ethernet traffic onto a single Ethernet access network. This is easy to do by selecting a NID that has the option to support T1/E1 circuits with the required facility loopback capabilities. In the case of Ethernet this would be wire-speed MAC swap or OAM loopbacks and for T1s this is ANSI in-band facility loopbacks.
This approach not only saves on the need to maintain dual network infrastructures, but also addresses the issue of T1/E1 exhaust where more TDM circuits are needed to the cell site but there aren’t any more available copper pairs to it.”
Schwartz: “Today, wholesale providers typically create two VLANs per base station. One could be implemented as EVPL and is required to backhaul T1s and data traffic with associated OAM messages from the cell site to the mobile operator MSC location. …Â The second VLAN to each cell site would be used by the wholesale operator for remote management and statistics collection. This VLAN could be implemented as an EVPLAN to allow management of many remotes on a single subnet.
“In order to support LTE X2 interface between eNodeBs, the wholesale carrier may implement another EVPLAN connection between cell sites to provide the mobile operator with local connectivity between adjacent eNBs for handover and local data connectivity purposes. …
“The wholesale provider is responsible for connectivity between cell sites and switching centers. Using stacking to separate traffic from different operators is one step, but they also need to monitor performance, ensure sufficient bandwidth and network redundancy.”
According to Schwartz, the case/justification for a cell-site demarcation device (MDD in this Carrier Ethernet ppt) will be usually triggered by more than one reason. Those reasons could be:
