24 Feb 2012
Overcoming Mobile Coverage & Capacity Barriers
Phil Sorsky, VP Wireless Sales for Europe at CommScope, discusses how operators are overcoming coverage and capacity barriers to support ubiquitous, high-speed connectivity
All the major operators are currently focused on deploying 4G networks, having known for some time that they will be key to overcoming the capacity crunch and ensuring growth potential.
In addition, 4G networks are designed to deliver a far lower cost per bit ratio compared to 3G networks.
However, ensuring that high-speed connectivity is available beyond a small number of hotspots in highly populated areas remains a significant challenge.
So how can operators ensure ubiquitous, high-speed coverage and capacity?
Small cells and bridging the capacity gap
Heterogeneous networks (or Het-Nets) are one solution to this issue that operators are currently considering.
Het-Nets combine numerous micro networks, consisting of multiple low power technologies such as picocells, microcells, distributed antenna systems (DAS) and Wireless LANs, to reinforce high-usage hotspots. Meanwhile the operator’s core cellular network - or macro network - delivers widespread, lower capacity coverage. The great boon for operators is that Het-Nets allow for a much higher quality of coverage, but also at a much lower cost.
The premise of Het-Nets is to seamlessly combine the micro and macro networks to ensure ubiquitous coverage and capacity. The macro network provides the coverage range, while the micro network provides the needed capacity for usage hotspots. Expect discussion at Mobile World Congress this year around the standards for network management protocols, which need to be agreed to handle this macro/micro hand-off.
CommScope ensures South African Stadiums are Covered for World Cup
Already the Asia-Pacific market is seeing a transition to this model, with countries like Taiwan rolling out macro/micro network sites at approximately a 12:1 ratio. That is, for every 100,000 macro network sites deployed, operators expect to set up approximately 1.2 million micro network sites.
Active antennas are also likely to be key to next generation radio networks. Essentially, they take all the functionality of the traditional remote radio head (RRH) and integrate it into the antenna housing. They consist of many small antennas wired in parallel. With an active antenna, instead of a single 60W RF amplifier radio, there is a radio behind every small antenna element.
Active antennas provide operators with a means to support larger volumes of subscribers (and thus generate more revenue) by providing the ability to sectorise coverage areas vertically for the first time. Most sectorisation is currently performed in the horizontal plane of the coverage area, but this opens up another avenue for capacity efficiency. Currently, if an operator has a sector at maximum capacity the only option is to split that sector or build another cell site. With active antenna technology, operators can take that sector, split it again vertically and come close to doubling its capacity – improving the service for subscribers and generating more revenue.
Another key benefit of active antennas is their ability to provide “graceful degradation”. Currently, if a remote radio head fails, the sector it was covering is dead, leading to immediate loss of revenue and inconvenience for subscribers until it can be repaired. Operators are also compelled to send a repair crew to the site immediately. With graceful degradation the problem is less urgent and so can wait for the next scheduled truck-roll or repair cycle to be carried out.
Skyline showing Basestation Antennas
This lowers operator’s expenditure, as they do not have to implement a new site visit just to fix one component. Thus graceful degradation allows service levels to remain high even when network hardware failures occur. This is taken a stage further by the ability of active antennas to “self-heal”. If one element of the antenna fails, intelligent systems can sense that that element is offline and redistribute the power to the remaining elements to maintain the quality of the radio coverage.
CommScope recently completed a 700 MHz LTE active antenna system field trial, which demonstrated the capabilities of active antennas in a true multi-site trial and provided a glimpse of what we can expect in the future. In particular, the ability to implement vertical sectorisation showed significant promise for increasing capacity, while the ability to tilt uplink and downlink elevation patterns was shown to further optimise performance and increase sector throughput.
We expect that fully 10 percent of base station antennas will be active antennas by 2015, so it will be interesting to see how prominent they are at Mobile World Congress this year.
One major complaint often leveled at existing mobile coverage is its unreliability for in-building connectivity. Technologies to support indoor wireless coverage are likely to see heavy emphasis this year. From public transport networks, to large public structures like stadiums, office buildings and residential blocks, the need for ubiquitous mobile coverage is a pressing issue.
Operators are intensely aware that subscribers now consider mobile connectivity an indispensable utility and demand instant access to a range of resources including e-mail, instant messaging, multimedia content and voice and video calling. If such services are not available, operators not only miss out on revenue opportunities but their customers may become frustrated by the lack of connectivity and potentially look elsewhere.
Underground Mobile Coverage
With approximately 75 percent of mobile calls originating or terminating inside building premises and fixed line telephony services in decline, operators know that ensuring effective in-building wireless coverage is essential. Unfortunately, the priorities for developers of office buildings, stadiums, hotels, shopping centres and other commercial structures are clearly aesthetics, efficiency and comfort and these same features are often the enemy of wireless technology, resulting in poor coverage due to the heavy use of thick concrete and steel during construction. This is particularly important as we move to 4G, which, at higher frequencies such as 2.6GHz, offers more bandwidth but penetrates structures less effectively.
Building owners and developers are now looking for cost-effective, high-performance and long-term solutions for equipping existing structures and new constructions with in-building wireless systems that will ensure occupants can maintain their wireless coverage demands well into the future. Indoor small cell antennas, coaxial cables, connectors and cable management apparatus can work together to homogeneously flood a building with wireless signals and deflect interference from the macro network outdoors as well as competing signal frequencies inside.
The most effective way to ensure in-building coverage is through a DAS, where radio frequency (RF) signals are routed through fibre or copper cabling from a single base station to multiple antennas located throughout the building. This has proven to be a highly effective and efficient way to distribute wireless connections inside a large building and eliminate ‘dead zones’. Another key attribute of DAS is that most systems support several frequencies as well as protocols (2G, 3G, and 4G). In order to provide good indoor coverage, this ability to support a large segment of the user community from one system, is a key capability not provided by networks based on single frequency/single protocol micro and pico base station products.
Looking beyond 2012
You can expect to hear more about all of the topics above at this year’s Mobile World Congress, as operators begin to agree on the standards and technologies that will deliver next-generation networks.
One thing is for certain, there is no “silver bullet” technology to providing ubiquitous coverage and robust network capacity – the winners in this transition to 4G will be those operators who combine technologies into solutions and roll them out expediently.
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About the author
Phil Sorsky is responsible for leading CommScope’s Andrew Solutions’ European wireless sales organisation in its efforts to provide the industry’s highest levels of support and satisfaction to customers from the Atlantic coast to Russia, and from the Nordics to the Mediterranean. Phil has more than 20 years of telecommunications industry experience, having worked for and made significant contributions to industry leaders such as Juniper Networks, Adobe Systems, Cisco Systems and AT&T. In his most recent position, Phil was Juniper’s vice president of sales for the United Kingdom and portions of northern Europe, where he was responsible for sales, technical support and marketing.
CommScope has played a role in virtually all the world’s best communication networks. We create the infrastructure that connects people and technologies through every evolution. Our portfolio of end-to-end solutions includes critical infrastructure our customers need to build high-performing wired and wireless networks. As much as technology changes, our goal remains the same: to help our customers create, innovate, design, and build faster and better. We’ll never stop connecting and evolving networks for the business of life at home, at work, and on the go.
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