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Data overload in the access network is becoming a big problem for service providers. Yet there are so many different answers to the problem that it’s sometimes difficult to separate fact from myth in terms of the effectiveness and efficiency of each solution. From self-optimizing network technology to small cells to Wi-Fi offload, there are definite benefits to each solution. Yet, many service providers don’t have the resources to implement every change to the network they would like. So how can operators make sure they pull the right levers to solve the most immediate problems?
There are three categories of requirements to consider when choosing a solution. The first is the impact that the deployment will have on the network capacity. Will it have a limited range or a network-wide impact? Will it impact a handful of subscribers or every subscriber? The second is deployment time. Will it take hours, weeks, months or even years to implement? The third is, not surprisingly, cost. Some technologies just cost more than others, regardless of the vendor. So let’s have a closer look at each one.
The first is SON technology whose impact on network capacity is very high. It typically increases capacity across all subscribers by 10% to 20%, which is a huge amount considering this is a software-based solution. The deployment time is very quick since SON solutions require no changes to existing network infrastructure. And yet, even with those advantages, the cost is low, compared to alternative solutions.
The second solution is traffic-throttling on the core network through the policy charging rules function, which can also have a positive impact on creating capacity in the network, and importantly, on differentiating the subscriber experience under congestion conditions. This solution can, for example, provide key customers a consistently high level of QoS even under congestion conditions, while deprioritizing QoS for other subscribers on a temporary basis. This requires integration of RAN data directly to the PCRF. In terms of the increase in network capacity under congestion conditions, traffic-throttling still does not have as great an impact as SON.
The third solution is Wi-Fi offload which is tricky to summarize quickly because it depends on the definition and scale of the Wi-Fi offload. There is “naturally occurring” Wi-Fi offload where users prefer Wi-Fi over the cellular data network in their home or office. MNOs benefit from this without doing anything. Then there is public-network focused WiFi offloading, particularly focused in dense urban environments, where most of the mobile network congestion occurs. The impact can be high or low depending on the environment and the scale of the deployment — and is typically just focused on cities. In this example, subscribers can be offloaded to available Wi-Fi networks with seamless authentication onto Wi-Fi, or more sophisticated ANDSF solutions where policies can determine when and under which conditions to offload a device to Wi-Fi, including determining quality of experience on the Wi-Fi or mobile network.
Then there is small cell deployment. Small cells in residential environments are relatively low-cost (especially if the service provider gets the subscriber to pay for them.) They can be deployed very quickly but have low impact per device with just a 20 meter range and 10 subscribers. Metro and micro small cell deployments require more planning and investment than any of the previous options in this list. The impact on the network depends, of course, on the scale of the deployment.
While the impact of extending macro cells can be high, so can the cost, especially with adding sites, rather than carrier adds or site splitting. And deployment time will be months.
And finally, the impact of a new spectrum is felt nationwide and can be very powerful. But it’s a long and expensive path to take, even with re-farming spectrum over the acquisition of new spectrum. Deployment can take years (even ignoring the political maneuvering before you get there). Costs can be astronomical.
There are no bad technologies here and we expect all service providers to deploy a combination of these approaches. Every one of these can peacefully co-exist within a service provider’s long-term plans. Yet, few operators have the resources for large-scale capital expenditure projects within any single financial year. That limits the options that will have an immediate impact.
Right now, the technology which has the biggest impact on network capacity is also the quickest to deploy — SON. That is why it is no surprise that SON is currently at the top of the list for most service providers that have not already deployed it.
