Guaranteeing Network Slices: The Role of 5G WAN Optimisation for Small Cells

The City of Sacramento has deployed 300+ small cells as part of a 5G Fixed Wireless Access deployment with Verizon. These deployments can only provide partial 5G coverage of a city like Sacramento. This is because of the relative transmission range of 26Ghz and 28Ghz spectrum. In fill is required with further small cells and coverage fill is required at mid-band Spectrums like 3.5Ghz.

The most effective way of delivering backhaul to multiple small cells sites is to use SD-WAN technologies over either Ethernet or microwave links. WAN Optimisation requires an intelligent-path control mechanism for improving application delivery and WAN efficiency. This intelligent path control and management of VPN tunnels needs to be integrated into the network slice management control plane function in order to guarantee the mission critical services.

The Network Slice Management control plane needs to manage end to end the latencies and traffic shaping. To do this the SD-WAN component for small cell backhaul must be an integral part of the end to end network orchestration.

Master Orchestrator Problems

The challenge for telcos face is how to integrate technology specific orchestrators. A 5G SD-WAN small cell solution could involve four unique orchestrators:

1. small cell orchestrator
2. with a 5G core orchestrator
3. a network slice orchestrator (NSSMF)
4. and multiple existing SD-WAN orchestrators

Most telcos have already deployed a SD-WAN products, involving multiple SD-WAN CPE vendors, where each CPE vendor provides a bespoke orchestrator. Industry examples include, the Cisco Viptela SD-WAN solution which uses a vManage network management solution within the orchestration / management plane and the Nokia Nuage SD-WAN solution that follows the same pattern.

To break this predominance of orchestrators (with lots of compensating logic) it is important to seek integration by API direct to the control plane. To be successful telcos may wish to examine how a vendor agnostic Network as a Service may improve their 5G orchestration strategy.