Robust backhaul solutions needed to meet data demand

Cambridge Broadband Networks believes its VectaStar backhaul system can boost network speed and capacity

Robust backhaul solutions needed to meet data demand

Cambridge Broadband Networks believes it has developed a solution to the problems mobile network operators are up against in maintaining a high quality service in the face of the increasing demand for data services.

The solution is the company’s VectaStar point to multi-point backhaul system. ‘It’s not a new idea,’ Lance Hiley, VP of market strategy at Cambridge Broadband Networks, told Wireless, ‘but we are the first to increase the power of the system to make it usable as a backhaul option.’

Hiley admits that the networks have alternative ways of creating extra capacity through more spectrum, smaller cells and the advent of LTE. LTE in particularly will improve data download and upload speeds, boost capacity, cut latency times and provide operators with a lower cost-per-bit. But it will not be in use in many countries before 2015. This leaves operators with an interim period in which they will have to manage the exponential growth in data.

The networks can also sweat their assets using HSPA and HSPA+ to provide faster speeds and more capacity. But Hiley argues that a new approach to backhaul design and operation can provide a low-cost alternative that is quick to deploy and which will meet future network capacity requirements.

Hiley says: ‘The networks have made the transition from voice networks and have now upgraded to being able to handle a lot of packet data. But this is creating challenges for operators, as they’ve got to not only upgrade parts of the network to handle the packet data, but they also need to upgrade their backhaul without hitting their capex too hard.’

Fibre offers the most reliable backhaul option, but it is very expensive to install into the areas that need it. Hiley says that microwave backhaul infrastructure offers an alternative solution. It is available now; it is small in size and energy efficient; and a microwave hybrid network support can be a key part of an all-IP network migration strategy.

Conventional microwave was good for earlier networks, according to Hiley, but as user density grows operators have to deploy more cell sites to increase the throughput to meet the increased demand from the larger number of customers. This is where it can be difficult to rely on conventional point to point networks, according to Hiley. Wi-Fi spectrum faces considerable interference issues and the adequate availability of spectrum is another problem, as is the need to find enough mast sites.

Hiley says there is a big structural difference between point to point (PTP) and point to multi-point (PMP). ‘PTP uses a single dedicated link to the cell site, along with a dedicated frequency to support that link. PMP uses a single frequency and a single access point (AP), along with a sectorised approach where you can connect to several APs.

‘By using a single frequency for the entire sector you are spectrally much more efficient. It creates the opportunity to set up a natural aggregation sector where you can backhaul several cell sites to a single AP,’ says Hiley. ‘So, you need less equipment and it is a cheaper and more efficient way to use your spectrum resource. It is a very efficient way to aggregate traffic through the core network.’

Hiley says Cambridge Broadband’s solution uses the concept of the core network, but out on the edge of the network. ‘It is very useful as it is very fast to deploy and capable of coping with wide variations of traffic from cell sites. It can dynamically allocate resources to different sectors.’

When LTE arrives, LTE enabled devices will be served by cells, which are controlled by eNodeBs. Smartphones communicate back to the eNodeB using the same principles. Cambridge Broadband’s extends that principle for its backhaul solution.

The eNodeB traffic is backhauled from the company’s VectaStar Terminal to an AP. A VectaStar Hub controls multiple APs, each covering a sector. Currently, the VectaStar system can support eight 10Mhz eNodeBs per sector, but when LTE is rolled out, they will be able to support higher capacities. Hiley says the company’s PMP model prepares the way for LTE and provides a very low cost option for backhauling LTE.

Hiley argues that Cambridge Broadband Network’s VectaStar system offers a strong solution for networks grappling with increased data traffic. ‘Because of the nature of the devices out there the shape and timing of traffic is changing. Tablets use a lot more data than iPhone or Android smartphones, and they are used in both the office and at home.

‘It is possible for these devices to be offloaded onto a Wi-Fi network at home or in office, but that may not always be the case,’ continues Hiley. ‘Some homes are using mobile broadband as their only connection, so there is a strong likelihood that the networks will see a change in the shape of traffic out to the suburbs at different times of day – and that may strain network backhaul.’

The VectaStar system allows network operators to provide blanket coverage within a sector, as it can dynamically allocate backhaul resource to different geographic areas to meet changes in location of data demand. Operators can reallocate capacity to different parts of the city as people move from offices to the bar districts and then to home out in the suburbs. That means capacity is not sitting idle back in the city centre in the evening or night time when it is not required.

Hiley says: ‘Backhaul needs a quality of service solution and ours is a carrier grade solution designed to integrate into a broadband network. It dynamically reacts to changes in demand without wasting resources at quieter times. So that’s why we think VectorStar is ideal for backhaul and that’s where the intellectual property resides for us.’

Hiley says Cambridge Broadband made a conscious decision to enter the backhaul space four years ago, as opposed to targeting the enterprise market.

‘We wanted to get fast time to revenue, so we went to operators building brand new networks rather than those that had a backhaul strategy in place and a mature network,’ he says. ‘So we are in sub-Saharan Africa, the Middle East and Asia, where we have $100m of equipment deployed in those areas.’

Hiley says that the company is now moving into Europe. It is trialling VectaStar with two of the largest Tier 1 operators in the UK in London and one other area.

‘We are very optimistic there will be some adoption fairly soon in Europe,’ said Hiley.

Written by Wireless magazine
Wireless magazine

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