On Tuesday at CTIA Wireless, the Small Cell Forum , an independent industry and operator association that supports small cell deployment, released a whitepaper outlining the opportunities and challenges facing public access 3G small cell deployments. The paper found that public access small cells could play a key role in providing additional mobile coverage, capacity and new services in both urban and rural areas.
The Forum’s research found that even with conservative public deployments, small cells could offload the majority of subscribers in many areas, drastically reducing network load. It found that with a ratio of one public access small cell per macrocell, 21% of users would be offloaded; this rises to 56% with four small cells and 75% with 10 small cells.
A major operator deployment consideration is whether to roll out open access small cells that would allow all subscribers equal access, or hybrid that prioritizes some users. By choosing hybrid access operators will be able to provide a “gold-class” service to certain subscribers or to organizations, such as police or first responders, who may help to cover the cost of deployment by providing small cell sites and potentially backhaul , says the Small Cell Forum.
Another important operator decision will be whether to self deploy or allow organizations (e.g. systems integrators, tenant owners, train stations or shopping malls or local IT staff) to deploy these open access small cells themselves without mobile operator personnel. The report concludes that SON (Self Organizing Network) technology will be required in both cases as networks will need to be permanently aware of their surroundings.
The paper also highlights interference challenges that operators need to be aware of and describes the recommended methods for overcoming these potential issues. These potential challenges include downlink and uplink interference as well as potential impacts from mobile connections in fast-moving vehicles quickly passing through small cells. The report says that although these challenges are very real, they can be mitigated using measures such as inter-frequency and intra-frequency handover, active hand-in as well as by re-calibrating transmit power and scheduling.
The paper also outlines the full range of backhaul options for public access small cells and how they vary in terms of availability, suitability, cost and latency. It notes that in rural areas there are the fewest backhaul options but that DSL and satellite have already been successfully employed.
“The next major stage in small cell deployments is going to be in public spaces. The entire operator community now appreciates that small cells are the key to long term mobile network capacity increases, as well as providing a means of economically delivering coverage in rural blackspots. Their impact will be especially dramatic in dense urban hotspots where small cells could quickly be carrying more users and data capacity than the local macro network,” says Simon Saunders, chairman of the Small Cell Forum.