Backhaul Core Network

The Core network is made up of ten masts or node’s each one is connected using a West/East

configuration on Carrier Class Microwave and Milliwave Radios in licenced spectrum bands. Out of

the ten masts five have direct fibre to at least one of the three Datacentres; Reynolds House

Manchester, Jule Data Centre Manchester and Telicity London. Once the traffic arrives at these

points the traffic routed to a pier or onto the internet via several tier one transit carriers.

The carrier class radios are able to manage the flow of high volumes of traffic to help load balance

and divert traffic to the nearest fibre with ultra-low latency, allowing us deliver stable and reliable

connections to the end user.

Please refer to diagram: QL-CORE-OVERVIEW

High Availability

The network is designed to “self-heal” itself in the event of a failure at a node or to assist when

maintenance work is required. The “self-heal” is achieved by allowing the carrier class radios to

manage the traffic in an East/West configuration; this allow us to control the traffic flow in either

direction and is able to automatically re-route traffic in the event of the loss of connectivity or if high

volumes of traffic require load balancing.

In the example (diagram: QL-CORE-FAILURE) we have shown two transmitter failures at the same

time on the network – The Arrows represent the flow of the traffic. Each Backhaul is equipped with

two radios in an East/West configuration. In the event of a failure the traffic is diverted via the

alternative transmitter and is delivered to the next hop that is then able to route the traffic to one of

the data centres in the core network before delivering the traffic to its destination.

Along with being able to “self-heal” the backhaul carrier class radios we are also able to re-direct

traffic to another node that is able to deliver the traffic to a datacentre in the event that the capacity

of the fibre exceeds 80%-85% of its available bandwidth to avoid “bottlenecking” traffic.

Example diagram: QL-CORE-CAP

Backhaul Network Latency

The carrier class radios used in the backhaul are able to deliver traffic from node to node in under

2ms in most cases it’s measured in μs. Even in the event of a node failing and adding additional hops

into the equation the backhaul network latency would never exceed 6ms (based on a maximum of

three hops) by using the network topology shown in diagram: QL-CORE-OVERVIEW we are able to

maintain a high availability of access while still maintaining low latency and Jitter across the entire

core network. This allows subscribers to use VoIP and other services that relay on a superfast and

stable connection to the internet.

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