The first 5G networks may be commercially ready by the end of this year. Mobile subscribers are within sniffing distance of lightning-fast 5G, a truly exciting prospect after years of build-up, speculation, discussion and…yes…some hype. 5G will open up use cases and business revenue streams that were previously impossible, as the new standard is a very different prospect from its predecessors. Yes, it is faster, but it is also a fully virtualized architecture that can unlock 5G’s most significant business opportunities for operators, and network slicing will be instrumental.
A new divide and conquer strategy
Network slicing is a way for operators to get a lot more from their infrastructure by offering numerous dedicated virtual networks specifically tailored towards a service or customer. It operates on virtual network architecture and borrows from the principles behind SDN and NFV. It has been in development for years. Now that 5G is becoming reality, the need to have a readily deployable network slicing technology becomes more urgent. For instance, Huawei and China Telecom have announced they are partnering to jointly develop such technologies.
Network slicing enables operators to define portions of the network based on the type of RAN, service, enterprise or geographic area. Operators would be able to define policies for each slice based on requirements of capacity, security, latency, connectivity (fixed or WiFi), coverage, SLA or features such as NB-IoT, energy efficiency etc. Operators can allocate their resources based on precise requirements and can avoid over-provisioning customers. In turn, this opens up the opportunity to expand the customer base and offer new, differentiated services.
Slicing stumbling blocks
With 5G fast approaching, the standards body, 3GPP, is expected to define specifications for network slicing soon and certainly by the latter part of this year. Its decisions will have far-reaching implications for operators rolling out 5G services to customers. With network slicing, the devil, as they say, is in the detail. While the benefits are well understood, pressing challenges remain. Here are six potential network slicing stumbling blocks that must addressed.
- Roaming
In theory, network slicing gives the operator unprecedented flexibility in defining the requirements for each slice. At the same time, customers expect the same level of service no matter where they are. So in practice, if slices are not standardized, it is unclear how any differences between regions or service providers would be handled.
- RAN re-designing
Since the slices must cater to all access — whether on Wi-Fi or on small cells or on macro cells — because proper co-ordination is required for handover of sessions across slices. Small cells and macro cells must be redesigned to work coherently and cater for specific slices.
- Spectrum slicing
Spectrum is also a shared resource. If an automobile OEM takes a slice, the operator must allocate end-to-end network resources across all geographic regions. This kind of dedicated service is costly. Operators will need to work with their enterprise customers to negotiate a model that delivers the desired QoE while still ensuring revenue for the operator.
- Scheduling issues
How about when a user’s device is entitled to multiple slices? Resource would be allocated per slice at the RAN level, but at the sub-channel level, slices would be combined. These scheduling issues need to be overcome to ensure multiple slices can operate as intended on each device.
- Service assurance
Slicing and dicing the network in this way creates its own challenges in terms meeting the SLAs defined for each slice at each point in the network. For instance, if low latency has been promised, then low latency is what the customer should get. But on what basis will the RAN prioritize scheduling if there are multiple sessions requiring the same thing?
- Slice management
Similarly, when managing slices, operators will need to check that individual slices are adhering to KPIs, meeting SLAs etc. That requires each slice to be individually scaled and managed. Slices themselves will need to ensure that end-to-end Quality of Service (QoS) is met. Where slices involve different vendors, interoperability issues must be surmounted.
Network slicing is a critical technology if the industry is to ensure 5G lives up to customer expectations and proves commercially viable for operators. It is a matter of months away and yet serious challenges exists when it comes to standardizing, scheduling and managing network slices in accordance with their SLAs. For some operators, 5G can’t come soon enough. If 5G is to flourish, then these challenges will need to be resolved fast.
