Modern building materials are particularly good at blocking RF signals meaning mobile signals beamed into buildings from outdoor macro cells are failing to provide adequate coverage and often capacity.
This has created a major problem as both workforces and consumers come to rely increasingly on mobile voice and data services. A Real Wireless study conducted on behalf of the Small Cells Forum in February 2013 showed that 39% of UK and 61% of US offices had poor in-building coverage, yet over 80% of total mobile data traffic is indoors.
An Alcatel-Lucent study undertaken at the same time revealed that 87% of businesses would switch provider to guarantee coverage, while 73% were interested in small cells as a solution. Clearly, there is an opportunity waiting to be fulfilled here.
Gavin Ray, SVP of products and marketing at ip.access, which has a range of 2G, 3G and 4G cells for residential, SoHo, SME, enterprise and public access, says: ‘If operators solve the indoor coverage issue well, there is a big opportunity to replace desk phones and reduce costs for enterprises. We think this will be one of the big stories of the year – and it is a way to help operators fund in-building coverage off their own bat.’
But is the industry ready to meet the in-building coverage opportunity? Generally speaking the answer is, yes. Unsurprisingly, there is no one obvious solution to fit every indoor deployment challenge.
The three key in-building coverage technologies comprise: distributed antenna systems (DAS); distributed radio systems (DRS), sometimes known as remote radio head systems; and standalone small cells. So, how do vendors see the in-building coverage market for these technologies today?
John Spindler, director of product management at DAS provider TE Connectivity, says: ‘I’ve been in this market for 20 years, but I’ve never seen this level of interest in in-building solutions before, which is very positive news for everyone in this space.’
Rob Bruce, COO at DAS provider Axell Wireless, agrees: ‘Certainly the market is very active right now. 3G and 4G especially have really pushed the situation to the fore as the higher-power, higher-speed, higher-capacity service people require inside buildings is quite challenging to achieve.’
Ronny Haraldsvik, chief marketing officer at small cell vendor SpiderCloud, adds: ‘2014 was the year when expectation of small cells really took off and industry vendors started to agree that different solutions are needed.’
Enterprises also need to consider what kind of future proofing they might require when it comes to the ability to scale their solution in terms of both coverage and capacity and the ability to accommodate new spectrum bands. ‘What you put in is about making a rational commercial decision,’ says Ray.
The technology is there then, but perhaps what is not really established yet are the go-to-market models: should they be operator-led, enterprise-led, building owner-led, or led by some kind of third-party, neutral host, for example?
Spindler thinks carriers are giving in-building solutions a lot more attention. ‘In the past they would install systems on a reactive, rather than a proactive basis. Here in the US at least, we are seeing their focus shifting from big venues to the enterprise space.
‘But I think we will see more and more engagement by the enterprises themselves to find solutions, as there is a growing dependency among the workforce on wireless,’ he continues. ‘And enterprises are starting to pay for those solutions.’
Axell’s Bruce agrees, saying: ‘When it comes to big infrastructures such as airports, stadia, shopping malls and some large office buildings and high-profile hotels, operators are prepared to invest to put systems in. But enterprises are now spending their own money by paying for and preparing the infrastructure and then readying it for the MNO to connect up to their network.’
However, Haraldsvik notes that IT departments in enterprises barely have the expertise to deploy Wi-Fi, so to expect them to be able to handle licensed systems is a bit of a stretch. Hence, we are likely to see a growth in third-party providers and system integrators, but we are not quite there yet.
‘Licensed small cells have to be endorsed by operators, unlike Wi-Fi,’ says Haraldsvik, ‘and we are just at the uptake point of indoor small cell adoption at the moment. But in three years or so, in-building systems will be much easier to deploy and the operators will be more relaxed about the possible effect they might have on their macro network. They’ll just let their channel partners set it all up.’
Cisco is trying to jump start this process by using its established Wi-Fi Enterprise Partner Program to deploy 3G/4G small cells in addition to offering Wi-Fi. ‘The best small cell fulfilment model for operators is to use the same distribution process and delivery mechanism they have for handsets,’ suggests Ray.
Spindler also points out that the third-party model will almost certainly be needed as operators do not have the manpower and resources or the maintenance capability to handle thousands of indoor systems.
Single or multi-operator
A major question for enterprises is do they want a multi-operator system or are they content with a single operator one? DAS enables multi-operator services, which help to meet the BYOD trend. However, DAS comes at a high price and tends to only be cost-effective in large venues.
Haraldsvik points out that there is no technological reason why you can’t provide a multi-operator small cell. In fact, Airvana unveiled its OneCell multi-operator enterprise small cell in June 2014.
‘But what it comes down to is who pays? If the enterprise pays, they generally want multi-operator; if it’s the operator they want to be the sole connectivity provider,’ says Haraldsvik.
‘A lot of big venues have seen DAS as the way forward, but individual football stadia have gone for small cells, so it’s interesting times as to whether a common approach emerges or a number of different ones,’ says Axell’s Bruce.
Ray believes both models will be used, but he argues that decisions need to be made within a grid of both product feature innovation and commercial innovation. ‘If you come up with new features that innovate in new commercial ways it is impossible to sell, because no one knows what works. But with small cells you are taking a known technology, but using it in new commercial ways.’
Wideband DAS systems have the advantage of being able to accommodate a wide variety of radio modes. But when it comes to deploying small cells the next key question for both enterprises and operators is whether to install 3G cells, or just 4G, or to opt for dual band 3G/4G cells.
The issue here is that if an enterprise wants indoor coverage now, most people will still be using 3G phones, but at some point in the future, when voice over LTE is ubiquitous, 4G small cells will be needed.
‘Some operators only want a 4G system,’ reports Haraldsvik. ‘It is easier for them to just do 4G, but then you are negating approximately 50% of the market or more (depending on the country). If that’s your business decision, so be it. But an operator supporting both 3G and 4G will have a bigger audience.’
SpiderCloud was first to market with a dual 3G/4G small cell (the SCRN-310 dual-band radio node works off a single chip with the 3G node capable of being upgraded to 4G) in June last year, while the likes of Alcatel-Lucent, Nokia Networks, Huawei and Ericsson are all working on small cells that combine 3G, 4G and Wi-Fi.
The market is also seeing innovation from the DAS providers responding to the small cell challenge with lower cost products. For example, TE Connectivity has teamed up with Alcatel-Lucent to combine DAS with small cells.
The DAS connects directly to the small cell baseband using a CPRI interface without any need to convert and then reconvert the signal as per conventional DAS. Alcatel-Lucent says this reduces the physical equipment by 50% and the cost of materials by 40%. Additional savings are also achieved by using less power, space and fibre.
Axell Wireless has pioneered an innovation it calls idDAS, which allows you to move capacity around a building to meet demand. Bruce says: ‘At the moment you have to design the whole system for peak capacity everywhere.
‘But in a combined hotel and office building, for example, the hotel will have low utilisation during the day and the office high, and then that usage pattern reverses at night. The operator will know the traffic demands and programme the idDAS to meet historical patterns.’
Similarly, the hotel concept can be used, where all the DAS equipment is hosted in a room in one building and capacity distributed to remote radio heads in neighbouring buildings, venues and transport hubs via dark fibre.
For enterprises the decision on what in-building coverage system best suits their needs will boil down to building size and staff density, total cost of ownership, the flexibility and ease of deployment of the system and whether they want multi-operator support or not.
Most vendors think there is a place for all three technologies and which is used will depend on the combination of factors described above. So, what is holding back the indoor small cell market?
Ray concludes: ‘I think the small cell vendors have done their job: the technologies are developed and the issues are understood. It is more about the operators recognising the opportunities, finding the right distribution models and then the budget for projects.’