Kumu Self Backhaul UE Relay User Guide v1.1
Kumu Networks, 960 Hamlin Ct, Sunnyvale, CA 94089, www.kumunetworks.com
2.2
Product Architecture
Conceptually an LTE self-backhaul Relay is an eNodeB with its Ethernet connection connected to a well
provisioned cellphone that talks to a base station. In the case of the Kumu Relay product the EnodeB is
external vendor equipment.
Figure 2 Relay data path block diagram
Additionally, the Kumu self-cancellation modules (indicated by the blocks UL and DL in the above figure)
allow the Relay to operate in full duplex approaching close to 2x the spectral efficiency of competitor’s
products. The self-cancellation is used to cancel the leakage of a given ports transmit signal into the
other ports receiver.
The CPU acts as a USB to Ethernet bridge as well as providing configuration, control and monitoring of
the unit. The EPC termination is provided by the EPC attached to the base station where the Ethernet
link from the attached eNode is encapsulated and forwarded via the internal UE air interface.
The control plane architecture is shown below where the physical layer connection is Ethernet for the
cancellation module UL and DL and external debug port and USB to the UE module inside the Relay.