Backhaul for mobile networks is critical to ensure speed and capacity as it relates to the transport of data and voice from distributed network sites to the network core. Traditionally mobile operators have not fully embraced satellite technology as a potential solution but now, thanks to a number of advancements in satellite technology, this is set to change.
Tim Peyla, Vice President Business Development at Sevis, explains the 'Why' and 'How':
Mobile Backhaul: The Challenges
Huge and highly competitive, the mobile services market requires those in it to deliver an outstanding customer experience. To do so and stay profitable requires them to do this at the lowest possible cost of ownership, with one of the most significant issues being how to provide scalable, flexible mobile backhaul. This became more challenging with the introduction of 3G and is set to get even harder with the roll out of 4G networks which are forecast to need to support 1,000 times more data traffic by 2020.
As a result more and more backhaul optimization technologies which reduce bandwidth have been introduced to the market. However, these solutions alone cannot solve all backhaul challenges, especially as the evolution to 3G and LTE grows. As a result there is a need for cost-effective 3G mobile backhaul over satellite communication for the global 3G/4G rural expansion, to relieve congestion caused by high data throughput technologies, such as HSPA, and for disaster recovery overlay networks.
Years ago, mobile operators have stayed away from satellite, preferring fibre, terrestrial and microwave solutions, for three main reasons:
But thanks to new technologies this is set to change. Let’s take a deeper look into how to do so:
1. Reducing Cost
As already mentioned, for mobile operators to stay profitable, it is important for them to deliver their services at the lowest possible total cost of ownership. The cost of backhaul, therefore, is one of the most important factors they take into account. Traditionally, satellite backhaul was one of the most expensive options, with a high price per Mbps for traditional widebeam satellite links. Thanks to High Throughput Satellites (HTS), though, this is no longer the case – even in areas supported by terrestrial access. Within the next two years, it is predicted that the cost of Mbps over satellite will drop six times, while traffic growth will double every two years, leading to a much more justifiable cost.
Another essential element in reducing the cost of satellite backhaul for mobile operators is Newtec’s multiservice platform Newtec Dialog, which enables greater efficiency on satellite. Finally, Sevis devices to reduce backhaul data rate needs are also key to bringing investment down. Caching, for example, allows mobile user data to be pre-fetched and stored at the edge of the network for instant access by the base station. This data can then be delivered during idle times on the backhaul network. Meanwhile, Remote Switching identifies remotely switchable calls and transparently switches the call at the remote site while ensuring the call is continually managed by the core network. This reduces satellite voice bandwidth capacity by 25 to 35 per cent, as well as eliminating the latency delay caused by a double satellite hop.
2. Removing Latency by Mitigating the Effects
After cost, latency is another big reason why satellite is challenging for mobile operators, with geostationary satellite link latency potentially resulting in a round-trip delay of 500 to 600 milliseconds. This affects the response time of 3G/4G data applications when sent over satellite, resulting in wasted satellite capacity, link under-utilization and poor performance.
While there is nothing we can do about latency, what we can do is look at the application side to help mitigate the effects of latency. Here caching also helps as a way of reducing latency.
Another method is TCP acceleration. With the Sevis Intelligent Backhaul Optimizer (IBO), the 3G protocol is decoded to access the TCP connection for each mobile user data stream and applies TCP/IP Acceleration. As well as minimizing latency, this also reduces satellite bandwidth needs, enhances mobile users’ experience and network performance, increases network throughput and improves network response times and reliability.
3. Ensuring Availability
The third and final perceived disadvantage that mobile operators have when it comes to satellite is the issue of availability. Some HTS systems are susceptible to fade during bad weather conditions, resulting in the service being disrupted. In such cases, a secondary communication path can be added at base stations so that voice and signaling can be routed over high availability terrestrial or C/Ku band routes, while the packet service runs over HTS. This maintains the use of the existing infrastructure and ensures voice and signaling stays on low latency and highly available communication paths but provides an alternative backhaul approach for service providers, therefore, eliminating the need to upgrade expensive terrestrial communication paths.
This method of dual route traffic has another advantage in addition to ensuring availability – enabling mobile operators to break in to new markets. For operators wanting to upgrade their system to offer 3G services in rural and semi-urban areas, the cost is huge. However, with Newtec Dialog® and Sevis Offload and Overflow solutions, operators can use satellite backhaul for 3G data only, with voice and signaling staying on low latency and high availability communication paths, such as terrestrial infrastructure. This method provides mobile operators with a low cost system to get 3G up and running until it is economically justifiable to install a microwave system.
With the explosion of big data generated by 3G and 4G services, scalable and flexible mobile backhaul is essential for operators which want to deliver an outstanding customer service. The huge cost associated with upgrading terrestrial infrastructure means another option is needed. With the advent of HTS, Newtec Dialog and Sevis, satellite backhaul provides this option at a very attractive price. The only question about satellite backhaul that should remain in operators’ minds, then, is…
…“When Do You Start the Switch?“
Vice President Business Development