Today, UK network operator EE showcased three innovative and complementary ways to provide temporary 4G service in case of outages due to flooding, major incidents and perhaps even for planned events. Adopting a three tier approach, these solutions encompass three different types of vehicle fitted with onboard small cells: rapid response pickup trucks, hexacopters and helium-filled heli-kites. Any of these could make a huge difference by restoring communication when disaster strikes.
Three complementary solutions
While their contractual requirements for the ESN (Emergency Service Network) to resolve a service outage within 3 hours will be satisfied by Rapid Response Vehicles alone, EE have been trialling two other innovative solutions. If approved for use, these could provide a comprehensive toolkit to improve network resilience and quickly restore service during critical situations. Each solution has an embedded small cell onboard.
It’s not impossible that each of these three solutions could be deployed in turn at the same site, quickly restoring service then subsquently migrating towards a medium term sustainable and wider reaching solution.
As an example, after the flood of Carlisle city centre shown below, the cellsite on the rooftop would have remained unaffected except that the power supply in the basement was rendered out of action for weeks.
UAV (Unmanned Aerial Vehicle)
Potentially the quickest to deploy, a hexacopter (6 propellers) UAV (Unmanned Aerial Vehicle) can be airborne and in service within 15 minutes of arriving onsite. These can be easily carried in a normal vehicle and can be flown over rivers, washed away roads and past any unsafe structures.
Since these are for commercial use, any UAV operator must be trained and licensed to fly it. A NOTAM (Notice to Airman) as shown on the right for the showcase must be promulgated beforehand to advise pilots (especially police/rescue helicopters) of their use. In the UK, they are limited to 400 feet vertically and 500 feet horizontally, and must remain in sight at all times.
Battery power for both the UAV propellers and the onboard small cell severely restricts flight time, but tethering through a power cable could allow these to remain airborne pretty much indefinitely. The other constraint is the weather, where wind and low cloud can prevent deployment.
The coverage footprint is around 1km. The payload is just over 2 kg. They can connect through satellite backhaul, relayed from the ground.
Rapid Response Vehicle
Many will be familiar with the term COW (Cell on Wheels), which is a traditional basestation fitted onto a truck together with a generator and some backhaul (typically point-to-point microwave). These are often used to provide temporary service at major outdoor events such as music festivals etc. A full size articulated lorry has been a common format in the past.
EE’s latest version is called a Rapid Response Vehicle and is designed to meet their contractual commitment for the Emergency Services Network. The equipment fits into a regular 4x4 pickup truck complete with 11.5m telescopic mast, portable generator and three sector cellsite. It can be commissioned within 30 minutes of arriving onsite, carrying enough fuel to last several days. The coverage footprint is around 2km depending on terrain.
There are anchor points at each corner of the truck with guy wires to the top of the mast. Thick coax cables connect the antenna to the equipment in the truck. A two-way dish provides backhaul from anywhere in the country through Avanti’s geo-stationary satellite service.
32 RRVS will be stationed at key points around the country, ensuring that the 3 hour SLA to deploy one anywhere can be met.
Sometimes referred to generically as balloons, heli-kites are not to be confused with the very high flying ones found in Google’s Project Loon. They are helium filled, tethered to the ground and incorporate a vane structure which turns into wind which also helps keep it aloft. The equipment can be battery powered or driven by ground power.
Heli-kites are much more resilient against strong winds, coping with up to 60 or 70mph. It’s lightning that is the biggest risk, and they would be lowered during any serious threat.
Towed to site on a trailer and inflated in-situ, these can remain on-station indefinitely and provide the widest coverage footprint of 4km or more.
EE plan to buy 10 heli-kites for use in unplanned (e.g. disaster) and planned (e.g. public events, major planned maintenance etc.) scenarios.
4G technology throughout
All these small cells are 4G only, using VoLTE for voice alongside high speed data with speeds up to 50Mbps or more. They could use any of the normal LTE spectrum bands at 800MHz, 1800MHz or 2600MHz (and perhaps even 2100MHz in future). There are no special or custom requirements for the smartphones apart from supporting VoLTE which is common in all high end devices today. EE’s CEO Mark Allera said they were making a strong push to equip all customers with compatible equipment.
Where deployed for use by EE customers, emergency 999 calls would also be accepted from any phone regardless of home network operator, as long as the device supports VoLTE – this is part of the regulatory licence requirement for all network operators.
Allsop Helikites are the UK private company which has pioneered this technology. EE said they scoured suppliers worldwide before settling on this local provider as their best choice. Managing Director Sandy Allsop told me his company had been refining the design for years - they have been used for many applications including video surveillance, GIS surveys, border patrols and aerial advertising.
Voltserver provide a unique and efficient method of delivering power by lightweight cable, running at some 300 volts but quickly and safely cutting out in case of any problem. Think of it as "Power over Ethernet" on steroids.
One of the two small cell suppliers is Nokia who used a 5W remote radio head and can also supply a full IMS “Network in a box” for completely standalone operation. EE have overcome some initial industry scepticism that the added delay (about 0.5 second) when using satellite backhaul would make voice calls unworkable. After extensive tests, they believe it works well and demonstrated it during the showcase. Richard Wilson of Nokia pointed out to me that even when connected to the network by satellite backhaul, any calls between smartphones onsite would be locally routed avoiding the satellite delay.
Parallel Wireless are the other small cell provider using their integrated CWS small cell which incorporates the option for mesh backhaul. What EE mean by this term is that the traffic can be relayed through a distant macrocell visible to the heli-kite but not below it. Mansoor Hanif explained that the kite could initially be raised to (say) 30 metres to assess if it could connect to any nearby macro, raised higher to (say) 50 meters if not and again to 100m if required. When a suitable macrocell connection is found, the Parallel Wireless small cell would automatically sense and select the best frequency band to operate in and configure itself into service.
Nigel Brown is the Lead for Resilient ICT Strategy in the UK Cabinet Office, Civil Contingencies Secretariat. This team deals with major crises including terrorist events and natural disasters. He told us he thought the technology was hugely exciting and gave several examples from the past when teams onsite (and victims themselves) had been without cellular service, making operations more difficult. One typical example where any of these solutions would have worked well would be the train derailment in Cumbria 10 years ago.
Coverage “on demand”
EE’s CEO Mark Allera doesn’t only see these solutions being used to respond to disasters.
“Looking ahead, I see innovations like this revolutionising the way people connect. In the future, why couldn’t we offer what we're calling 'coverage on demand'? What if an event organiser could request a temporary EE capacity increase in a rural area, or a climber going up Ben Nevis could order an EE aerial coverage solution to follow them as they climb? We need to innovate, and we need to think differently, always using customers’ needs to drive the way we create new technologies."
Here's a short video of the heli-kite and drone in operation, with commentary by Mansoor Hanif of BT/EE (Apologies for the poor quality audio)