Our recent case study of the City of London highlighted how urban small cells deployed at street level are becoming a viable solution for busy metropolitan areas. Nokia have also been active in New York and other US cities, where densification is essential to maintain high performance and customer satisfaction. We review a Nokia case study for a major US network.
Urban small cells (sometimes also named metrocells) are compact and discrete mobile phone basestations, unobstrusively located in urban areas. They can be mounted on lampposts, positioned on the sides of buildings or found indoors in stadiums, transport hubs and other public areas. They provide excellent mobile phone service, delivering very high data speeds and capacity, solving the problem of growing data traffic demand cost effectively.
These small cells are usually owned and installed by the mobile network operator themselves, who plan, manage and maintain them in the same way as their larger macrocell cousins. However, the large numbers of metrocells change the way in which the industry operates.
There are three important distinctions that define an urban small cell:
- Operates in licenced spectrum. This means that unlike Wi-Fi where the frequencies are shared with anyone who wants to use them, a network operator can design and manage the radio coverage and interference throughout, achieving much more predictable results. This is especially important in high traffic, busy environments. Some metrocells also offer Wi-Fi as an option
- Much smaller than a macrocell. These compact units are of a similar size to a laptop or tablet, rather than a large cell tower or mast. Their unobstrusive format makes them much easier to find suitable sites. Often they are disguised and difficult to spot. This makes them much easier to install too.
- Lower RF power and capacity than a macrocell - typically 1W or 2W, maximum 5W. Typical urban small cells might handle 64 or 128 concurrent active voice or data sessions (products vary widely in capacity) and can stream data at the highest 3G and 4G speeds. They do this over much shorter ranges than a macrocells, 100 metres or so compared to several kilometres radius.
A cluster of urban small cells can deliver very high levels of data throughput, making them very cost effective to handle urban areas with strong demand. Their comparative lower cost per unit means they can deliver the same extra capacity as macrocells for less than half the cost.
In this urban small cell section, we look at the implications for the industry, from the new technology involved to how this will impact the commercial relationships.
I visited the City of London, the 1 square mile central business district within the metropolis dominated by international finance and big business. The governing body recently awarded a concession that provides free public Wi-Fi in return for street level small cell sites. Services have been launched after only 28 weeks. I spoke with both City officials and the project manager to appreciate the benefits to all involved.
There are various types of company offering to take the pain out of urban small cell deployment. JCDecaux, well known internationally for their highly visible street furniture, seeks to capitalise on their large estate of suitable sites. I spoke with Marina Marjanovic and Benoit Paquin to understand the scope and uniqueness of their approach and which regions worldwide are showing greatest interest.
There are a wide variety of potential locations for outdoor urban small cells, but there can be many issues to arrange and secure the best sites. What actions can be taken to streamline the process and open up wider access to suitable sites? Following on from our previous articles on regulatory approval for the RF power radiation and for local planning/zoning approval for the physical size/format, we now take a look at finding and securing the most suitable sites. Is there an opportunity to create an online marketplace?
Widespread variations in national and international regulations for Urban Small Cells are one of the hurdles holding back faster deployment. What can be done to standardise and expedite this? Here we consider aspects of RF transmit power rather than physical planning/zoning..
Progress with urban small cells seems to have been much slower than originally forecast. Has this market died, gone to sleep or is it just resting? For another perspective on this, I caught up with Arthur Giftakis, SVP Engineering and Operations at Towerstream, a leading Fixed Wireless Fiber Alternative provider, offering shared wireless infrastructure and backhaul solutions in top urban U.S. markets.
Openreach, the UK national wireline infrastructure provider, launched a new service this month called MiiS. It offers to sub-let any of its telegraph poles for use as a small cellsite, providing a small street cabinet, backhaul, mains power and even a pole-top antenna. This promises to make it easier for network operators to target and deploy large numbers of smaller outdoor sites, especially in suburban areas, accelerating take-up.
While it is the prerogative, and perhaps the duty, of Network Operators to stretch the capabilities of equipment manufacturers, we risk delaying the wide scale deployment of small cells, and their associated capacity and user experience benefits, if the MNOs and vendors spearheading its adoption are unable to make some choices.
Cost and ease of deployment in city environments are both critical requirements for metrocells but to achieve these we will have to be selective about other highly desired attributes.
We can't risk demanding too many requirements and asking too much of developers.
The most demanding locations of growing mobile data demand are in the urban city centres. Metrocells – small cells designed to provide huge capacity in public areas – can provide this more cost effectively than traditional macrocell approach. But will the limited number of locations mean that those operators who move quickly to acquire premium sites gain competitive advantage, or will this cause different commercial models and other pressures to take precedence?
Advertising billboards, street vendors, parking spaces, charity recruiters all compete for space in our busy urban areas.
There are four major factors we commonly hear network operators talk about when looking at how they will deploy metrocells. These are not the only issues, by any means, but are the most common:
Metrocells are compact and discrete mobile phone basestations, unobstrusively located in urban areas. They can be mounted on lampposts, positioned on the sides of buildings or found indoors in stadiums, transport hubs and other public areas. They provide excellent mobile phone service, delivering very high data speeds and capacity, solving the problem of growing data traffic demand cost effectively.
Planning/zoning regulations have been the cause of many delays in deployment of urban small cells in many parts of the US. Activity at state and federal levels is causing strong debate which is leading towards new Federal legislation.
We often hear how uncooperative municipal planners can be regarding approval for siting of urban small cells. Network operators have pushed hard at national levels to relax the rules, with success in many countries. One Californian city planner, speaking on a personal basis, provides an opposing view and cites examples where the rules have been abused and suggests ways to accelerate the process for the benefit of all.
One aspect that has been holding back more rapid deployment of Urban small cells relates to local planning authority approval. This is more about the form factor (size, positioning, colour etc.) than the RF emissions, but also includes access arrangements where installation work may require temporary street closures.
Erol Hepsaydir, Head of Ran Strategy at Three UK, gave an excellent presentation at HetNet world last month, outlining the perspective of how he sees future technology meeting their goals of coverage, capacity and quality. Key points included differentiating RAN features that do/don’t need device support, tricks and tips for small cell integration and the importance of SON.
Telephone briefings and conference presentations are very useful learning opportunities, but nothing quite beats a site visit where the practical issues can be explained and discussed. I walked around several city centre areas of London with Andy Sutton, Principal Network Architect for EE. He showed me their current physical installations, explained how they will evolve and pointed out enormous range of potential sites for future urban small cells. In this first of two articles, we look at the macro, micro and small cell sites that will make up the dense urban HetNet of the future.
An important part of the business case for metrocells is that they need to have a relatively long, trouble-free working life, with minimal maintenance. This leads to demands for plenty of processing power "headroom" to allow more complex software to be remotely downloaded in the future, RF front ends that can cope with either 3G or LTE, and long-life components that won't age prematurely or fail quickly.
The original small cells, femtocells for residential and enterprise customers, used standard broadband internet for their backhaul connections into the mobile network core. Metrocells, deployed by operators for widespread public use in streets and densely populated urban areas, typically don't have this option. This has led to a range of innovative new wireless products both from established and upcoming vendors.
Mobile data traffic is doubling annually. Future predictions are for total mobile data capacity demand of anywhere between 20 and 50 times within 5 years. The greatest demand both today and in the future is concentrated in the dense urban areas.
While operators have just about been able to keep up so far (some less so than others), there is wide recognition that something radical will have to change to deliver the capacity required.
And it's not just about more capacity per se, it's about the overall speed and quality of service each customer perceives.