We've heard a lot about Small Cell hosting services in Europe but not that much in other countries. Towerstream has been quietly building up a portfolio of suitable sites for urban outdoor metrocells across the US, and we spoke to Arthur Giftakis, VP Engineering and Operations, to learn how that came about.
His view contrasts with the street level/lightpole only deployments promoted in other countries, serves outdoor rather than indoors, and suggests wholesale Wi-Fi expanding to multi-operator cellular small cells may be the long term solution.
This US listed company (TWER:NASDAQ) was founded 10 years ago to offer fixed wireless access and has grown to serve 16 markets across the US, mostly by organic growth but also through a few acquisitions (e.g. firesales of struggling small local fixed wireless (operators). They've built a comprehensive wireless IP backbone which delivers anything from 1Mbps to 1Gbps for business customers, with double digit quarterly revenue growth.
They recently formed a new subsidiary company, HetNets Tower Corporation, which is similar to a tower rental business and leases space for Wi-Fi and Small Cells in urban outdoor rooftop locations.
Moving into Wholesale Wi-Fi for data offload
"As the iPhone and other smartphone traffic took off and cellular operator networks started to become capacity constrained, we looked at offering a data offload solution to alleviate their capacity issues. After trials, we settled on Ruckus Wireless as our Wi-Fi access point partner and have become a premier customer. We deployed over 200 public Wi-Fi access points across Manhattan first, and marketed the service to cellular carriers, MSOs and internet companies.
"We soon found we had a crazy number of data sessions and traffic flow, and realised this was an opportunity that could grow fast. We focussed on site acquisition of rooftops suitable for both Wi-Fi and small cells - typically 2-3 storey rooftops. This has become a bit of a "landgrab" scenario, with premium properties such as at Times Square strongly in demand. We now have almost 2,000 outdoor Access Points deployed across Manhattan, and substantial deployments in Miami, Chicago and San Francisco.
"Our wireless backhaul infrastructure is a real differentiator – most of these sites don't have fibre connections in place. We use standard 400Mbps point-to-point microwave radios from Dragonwave, Siklu and Ceragon, meaning we don't have any real backhaul capacity issues. Each site has its own high capacity Ethernet switches, with 24 or more GigE ports equipped with PoE (Power over Ethernet) allowing us to connect virtually as many devices as we want. Each site has plenty of access, space, power and backhaul to meet our customers' needs.
"So far, we are finding our proposition of being able to provide premier locations with backhaul available over our fixed wireless network to be fairly unique
First to achieve WBA ICP certification
"The Wi-Fi Broadband Alliance publishes standards on the technical and commercial interfaces between wholesale and retail Wi-Fi service providers. We are proud to be the one of the first to gain Interoperability Compliance Program (ICP) certification. This makes it much easier to wholesale Wi-Fi services to any operator. It's now almost as straightforward as setting up another GSM roaming agreement – the commercial and technical procedures are all in place.
"Hotspot 2.0 and Passpoint will also make it easier and transparent for customers to connect through Service Provider Wi-Fi, which will continue to be an important component of a wider package of wireless services provided by network operators."
Like a tower company, but for small cells
"There are several large and well known tower site businesses, such as American Tower and Crown Castle, who own many sites and physical towers across the country. Perhaps surprisingly, they have less penetration in the urban areas
"We effectively operate like a tower company, renting space and power but also backhaul in capacity increments of 50Mbps. Our locations are suitable for small cells and Wi-Fi access points in the urban high traffic areas."
2-3 storey rooftop sites rather than at street level
"We've been primarily looking at 2 to 3 storey rooftops, which form about 95% of our portfolio, with a few first floor or awnings for special situations. We have not used light poles/lampposts because of power and backhaul issues.
"Being down low at street level has advantages – the closest antenna to a device always wins – but the flip side is if you position at door height, you would have a much smaller coverage footprint. We've found that by using Ruckus Wireless and taking advantage of their smart antenna technology using beam forming, we can achieve a larger Wi-Fi coverage outdoors of up to 300-400 feet radius even in very noisy RF environments. These APs handle noise very well, reacting to interference and adapt easily to a 2nd storey rooftop building location.
"By contrast, we've found some street level locations can become temporarily blocked by trucks parking etc."
Evolving to LTE outdoor small cells next
"Initial research with our partners indicates that LTE small cells would be positioned on the rooftops with antennas tilted down to avoid macrocell interference.
"We expect each of our sites to evolve to host multiple small cells from different operators, serving both 3G and LTE. Some of these cells may have an external antenna, and there's plenty of space to support either multiple or shared small antennas on the roofline.
"So far, we've not seen much interest in 3G small cells – here in the US, requirements are for LTE and possibly dual-mode Wi-Fi/LTE products.
"Timing and sync will be important for LTE and is commonly provided using GPS. However even in outdoor Manhattan, you are often limited to a sky view of only two satellites which can become a challenge in some locations."
Carrying outdoor rather than indoor traffic
"Building construction materials and higher frequencies used for Wi-Fi and cellular make it more difficult to penetrate signals into buildings from outdoors.
"Today, a large number of macrocells deployed in downtown Manhattan are pointing into skyscraper buildings to serve traffic indoors. This isn't sustainable, and we'd expect more indoor capacity to be installed in the future. One method involves the latest 5GHz Wi-Fi frequency band, which rarely leaks out from modern buildings, reducing interference and allowing frequency reuse both inside and outside.
"Our approach is to provide capacity outdoors in the street and we do not attempt to penetrate inside buildings from our outdoor deployments."
It appears these views are shared by Ruckus themselves, with their CEO expounding co-existence between Wi-Fi and 3G/4G small cells in this recent MobileWorld Live video interview