The top priority of any wireless provider is to make sure that the wireless signal from a device gets into the ground as soon as possible. To do this, it’s crucial to make efficient use of the available spectrum.
The amount of wireless spectrum and bandwidth available to operators is ultimately limited, so it’s attractive for them to decongest their networks using other technologies as appropriate; for example, if customers are using their handsets beside a Wi-Fi point, it’s possible to take them off the wireless network to free up bandwidth. Through ‘Wi-Fi offload’, major opportunities are opening up for fixed-line operators, who can backhaul offloaded traffic through their networks.
According to Mervyn Kelly of network specialist Ciena, offloading is an obvious way for operators to reduce traffic on their networks: “From a backhaul perspective, the bandwidth is the bandwidth – all you’re doing is moving it from a base station to a Wi-Fi offload point”.
Currently, Wi-Fi architectures work via an access point that receives a signal from the device; the signal is then carried back to a hardware-based controller, with each controller able to handle between 16 and 32 access points. Fourth generation wireless LAN architecture allows Wi-Fi to be deployed in a cloud-based secure scalable environment, separating the control plane from the data plane.
The data plane remains with the access point, but the control plane is moved to a different layer on a data centre server, allowing for multiple access points to use a single software controller. This enables service providers to build a scalable secure Wi-Fi network with hundreds or even thousands of access points distributed across a large area; they can then offer Wi-Fi services as well as providing Wi-Fi offload to mobile network operators.
Kevin Morgan of network equipment provider Adtran notes that Wi-Fi offload could be a huge growth area in emerging markets. He explains that the Wi-Fi Alliance has developed a new technique called Hotspot 2.0 which defines the handoff mechanisms between the Wi-Fi networks and the cellular networks. Entering a Wi-Fi-enabled area allows users to transfer their data and voice connection seamlessly onto the Wi-Fi.
There is a limit on the spectrum available in the wireless cell tower space to accommodate the growing demand for bandwidth, so mobile operators are looking to offload as much of this bandwidth as possible. They can’t do this without certain security standards and authentifications, and this is handled by Hotspot 2.0. Scalable cloud-based architectures provide a quick path for service providers to participate in another revenue stream, offering Wi-Fi offload as a wholesale service to mobile network operators.
“This technology is cutting-edge”, explains Morgan. “It’s coming in the next year or so. For both fibre and copper, it’s about using aggregation technologies to take the signal back from the network and do something useful with it.”