Anxieties over whether the new 4G Emergency Services Network will match the current Airwave coverage across the UK have been among the chief concerns of end users in Police, Fire and Ambulance organisations ever since the project was announced.
Steve Whatson, Deputy Director Delivery, Emergency Services Mobile Communications Programme (ESMCP) in the UK Home Office, was quick to address the issue at a session entitled ESN – Coverage held at the British APCO 2016 conference and exhibition in Telford this week (22-23 February) assuring delegates that ESN will match the Airwave coverage.
Whatson said that coverage for major (96%) and minor roads (87%), outdoor hand portable devices (87%) and marine coverage (87%) will be matched like for like. In the case of air to ground (A2G) it will be better. A2G is measured in two parts: from ground to 500ft and from 500ft upwards. Currently, A2G extends to 6,000ft, but this will be doubled under ESN to 12,000ft.
Whatson also pointed out that coverage is not one single piece, but will be comprised of a number of different elements, which all need to mesh into one seamless network run by the ESN Lot 3 main network provider - EE. This includes:
• UK mobile operator EE’s main commercial 4G network
• Extended Area Services (hard to reach areas of the UK where new passive sites are to be built under a separate contract and then equipped with EE base stations)
• London Underground
• Marine coverage – to 12 nautical miles
• Special coverage solutions.
Mansoor Hanif, Director of Radio Access Networks at EE, sought to address user concerns over coverage, resilience and availability. He began by telling delegates: ‘The base line for ESN is like-for-like coverage with the Airwave network, but we are looking to bring in exciting innovations that will make it be the best in the world. Our ambition is to be as good as the leading networks in Korea, Japan and the US.’
Hanif said that the operator was not arrogant enough to think EE is the best at the moment – far from it. He said that innovative solutions are needed to match Airwave because that cannot be done by the conventional methods normally used for building mobile networks. This is especially the case when the operator is moving towards providing an ultra-reliable network based on a commercial network with millions of consumer users.
Coverage and capacity
EE is building a separate core network dedicated to ESN users, enabling it to easily give priority to emergency services traffic, although it will share the same spectrum and backhaul.
Hanif sought to reassure end users in the UK emergency services that the EE network would deliver ‘unbeatable coverage and capacity’, explaining that the company is building out its network to comprise some 19,000 macro sites and some smaller sites.
Capacity is of course another concern, but Hanif said: ‘We would never have bid for ESN if we didn’t think we had the capacity to do it. We have 20 times more spectrum than Airwave, so we are confident we can handle the volume.’
He noted that EE is building in extra layers for capacity and can now take advantage of new technologies never available before now, such as carrier aggregation (where disparate bits of spectrum are combined to provide more throughput capacity to meet traffic demands).
EE won some 800MHz spectrum in the 4G spectrum in 2013, and is now rolling that out to its sites. ‘You will not have seen the impact of this yet,’ explained Hanif, ‘as it has just been coming on line in the last few weeks. But we have thousands of sites being upgraded to 800MHz (which propagates over longer distances and is better at penetrating buildings than its other 4G spectrum holdings).
Hanif also pointed out that one other crucial application; voice over LTE (VoLTE) is now being switched on. ‘We have done five cities so far and today (22 March) we switched on central London. On day one we had a dropped call rate of 0.3 and we see that dropping to below 0.2. In Korea, where they have had it for some time now, they have achieved a rate of 0.18.’
Summing up, Hanif said: ‘What’s coming in the next few years will be quite different from what you’ve had before.’
Turning to the issue of reliance, Hanif said that EE was deploying a range of solutions including battery backup, fixed and mobile generators, resilient transmission, flood defences and rapid response vehicles.
Hanif pointed out that the UK suffers from 60,000 power cuts a year, so EE is increasing its independent battery backup at some of its sites using fixed and mobile generators to provide enough time to get repair teams, which may take up to four hours to reach a site, to get there in time.
In terms of beefing up transmission resilience, Hanif said EE is looking at implementing ‘multiple routes back to the network to connect every base station to the core network’. These multiple paths will comprise wireless links, satellite and leased lines – and EE is also looking at some other innovative solutions (see below).
‘We’ve been working with the Home Office and Cabinet Office on flood defences,’ said Hanif. ‘We recognise flooding will happen, so we’ve made a detailed study of flood plains in the UK which have a 1 in a 1,000 risk of flooding and are working out how to best defend radio sites in these areas. We will have hundreds of rapid response vehicles if the sites fail due to flooding.’
New operational processes
Getting permission to access sites from landlords is a major problem for mobile operators. Hanif pointed out that: ‘We often fail to fix sites because the landlord won’t give us access. We need to have the right to fix a site when it impacts on people’s services.
‘We also need to be able to carry out preventative maintenance and we do need to uplift our service here. We need to be proactive; if we know a storm coming, we can send out mobile generators. We need to be smarter, quicker and more effective at doing that,’ said Hanif.
He added that new legislation will certainly help improve access rights for mobile operators. ‘We need increased powers to enforce access. We need proper rules around that so we can go in and fix things quickly. We have put our views into Government on this, but we are not sitting back.
‘We are proactively looking at our contracts with site owners and we have 15,000 of them under review. We are making sure we now have 24 hour access, especially for maintenance,’ said Hanif.
Mission critical standards for LTE
Hanif added that the network still needs to be ultra-reliable and incorporate the new mission critical features and functionality being written into LTE by standards writing body 3GPP. ‘The mission critical features in Release 12 will help us enhance and support security, allow us to prioritise calls, and deliver a high availability for resiliency.’
Just to update 3GPP’s work, news came through last week (15 March) that in the second week of March at a meeting in Gothenburg, Sweden, 3GPP ‘froze’ work on LTE Release 13. The good news is that was able to complete work on writing the standard for Mission Critical Push-to-Talk (MC-PTT) functionality. There were concerns last year that this would not be achievable within the designated time frame.
This leaves work on mission critical video over LTE and mission critical data over LTE for Release 14, along with some other functions. As regards ESN, pre-standard solutions will be used until the relevant standards have been written by 3GPP.
Innovation for rural coverage
Hanif said that EE is looking at a number of innovative solutions to ensure service continuity on ESN such as satellite backhaul, airborne disaster recovery using UAVs etc, mobile LTE network-in-a-box solutions, marine ROVs for flood areas and so on. ‘This is beyond the usual, what we are doing around ESN,’ he said.
Coverage in rural areas is, as any UK consumer knows, still a big issue. Hanif said EE will be deploying small cells with in-band backhaul, and pointed to its small cell trial with Parallel Wireless. ‘This is a mature trial now and we will be rolling it out to rural areas. It uses a multi-path solution, a small cell mesh network with two exits, so it is more resilient.’
Backhaul in rural areas
EE is also looking at deploying rural small cells with satellite backhaul. Hanif reported that normally it takes 480ms to complete a round trip via satellite, but recent EE proof of concept trials undertaken with partners has achieved 100Mb speeds.
‘It’s a trick to get around the physics,’ said Hanif. ‘We are not the first to do this, but in terms of VoLTE we believe we are first to test this and get it out. We will use this satellite connectivity to many sites where we do not have backhaul, such as the Scottish Highlands and Welsh Valleys.
‘Many Airwave sites do not have much traffic so we think we can use satellite, or at least use it as a back-up if the main solution fails. We will also use it for some of the ROVs where needed and for temporary coverage solutions.’
Hanif added that following EE’s takeover by BT, there are some products from its parent company it can exploit. ‘BT has some small cell products we can use, plus we can access telegraph poles via Open Reach. We’ve been slow to take them up on that, but we are looking to leverage them, especially for small cell mesh technology.’
EE is also looking at coverage solutions for railways including tunnel coverage and infill coverage in railway cuttings. He pointed out that Italian rail tunnels got coverage years ago, but that UK mobile operators have not been able to get that access.
Airmasts for disaster recovery and emergency response
Another new area EE is checking out is the possibility of using ‘airmasts’ to provide additional coverage. Meshed small cells, network in a box and repeater solutions are becoming available for these ‘airmasts’. Hanif said he and a number of EE engineers attended a demonstration of airmasts on Mt Fuji in Japan to see the concept in action.
‘We will use something slightly different in the UK. For example, if we have 15 sites out due to flooding, we can install coverage in balloons, which have 30 days flying time and are strong enough to withstand storms, or by using UAVs – perhaps tethered drones with power cables and optical fibre connected them - or helicopters could be employed.’
EE is also looking at mesh network techniques to enhance 4G maritime coverage. Hanif said he has set his team the task of connecting the 43 ferries that sail among the Scottish Islands. ‘We are looking at deploying small cell solutions on lighthouses, which can work if there is power available. We mesh the small cells up and that provides coverage to the ferries, which carry a small cell on board. The ferries hook into the mesh network. We are trialling the solution this year at a couple of lighthouses.’
Hanif added that EE is considering whether something similar can be used to connect UAVs as well. That kind of solution would be very useful for fire services, he argued. ‘If the UAVs are connected by 4G into our network we will know where they are and we can control them. Maybe we can try this in the islands too; we are looking for a partner to trial this, perhaps in 2017.’
Hanif concluded by saying that 4G is a much more stable standard than 3G and it comes with a roadmap that will enable EE to increase coverage, capacity and resilience as 4G develops. ‘1 Gbps capability is coming and we will be able to smoothly evolve our network to 5G when that comes in around 2020.’
EAS – Extended Area Services contract
ESMCP’s Steve Whatson provided an update on the EAS framework contract, which will provide mast sites for coverage in areas where EE will not build its own sites. Instead, other companies will bid for the right to acquire, design and build passive radio sites. Once complete, EE will come in and install its 4G radio equipment.
Whatson said: ‘The ITT (invitation to tender) for the framework is closed and we are now evaluating the submissions. Six to eight companies will be on the framework and who those are will be announced around the end of May 2016. We will then launch mini-competitions for those companies to go and acquire, design and build those sites.’
He added that to help speed up delivery, separate site surveys in the EAS designated areas are being carried out, so companies will be given those in their information packs.
EAS Backhaul contract
Backhaul for the EAS radio sites is the subject of a separate ITT contract. ‘We are looking at solutions in conjunction with Motorola Solutions (the Lot 2 User Services provider) and EE to see if we can use satellite for this. But we are also looking at fibre or microwave wireless solutions which will connect the sites to the main network via mini-hops,’ said Whatson.
EAS Facilities Management contract
There is also a further separate contract to manage the EAS sites once they are up and running. The ITT will come out later this year, as this aspect is not as time critical as the other two EAS contracts.
EAS planning permission
Responding to a question as to whether work on planning permission can proceed ahead of the other EAS contract, Whatson said: ‘I think by time we have finished the site surveys we will be into the mini-competitions, so we maybe can’t do planning permission before.
‘But we have engaged with local authorities and National Parks England to let them know what is happening. We have learnt the lessons from the Mobile Infrastructure Project (MIP). Yes, we recognise that National Parks are a challenge, but they also know that these areas need coverage.’
The air-to-ground contract has been a tricky one to find a solution for, but there is one in place now. It will be a 4G solution using TDD (Time Division Duplex) spectrum. The Government has found some extra spectrum for the service (in the 3.2GHz band?) according to ESMCP’s Steve Whatson.
London Underground coverage
Like the air-to-ground contract, the London Underground Ltd (LUL) has also been a thorny one to find a coverage solution for. But Whatson declared that there will be full coverage across LUL.
‘At the moment LUL uses leaky feeder coverage down the tunnels connected to Airwave TETRA base stations,’ said Whatson. ‘Going forward, we will look to deliver coverage to the stations using the existing Wi-Fi system. We will either put a 4G card in the Wi-Fi access points or deploy a separate 4G base station alongside them with coverage back out to the road, so it becomes a seamless part of the EE network enabling users to roam straight across.’
However, the station platforms system and tunnels will be closed to the public and is for use by the emergency services only. Whatson said: ‘We have no choice but to use the leaky feeder cables in the tunnels as there is no room for anything but a cable in the tunnel.’
Questioned as to whether home routers might be incorporated into the network to aid indoor coverage, Hanif said: ‘We are hoping we can make them ESN capable, but we are not really concerned about residential homes, it’s more about ensuring coverage in shopping centres and rail stations and other large venues.
‘We have 4G small cells and DAS (distributed antenna systems) solutions ready to pull the trigger on that, but whether that’s home routers or something else we need to make sure it is properly integrated into the macro network. That is very hard to do on 3G, but much easier on 4G.’
Direct Mode Operation
The ability to communicate directly from radio to radio without going through the main network is a key function in professional mobile radio systems such as the TETRA system currently used by the UK emergency services on the Airwave network. 4G was not originally designed with the functionality for direct mode operation, or proximity services, as it is sometimes known.
Steve Whatson reported that work on DMO is progressing. ‘There are reasonable questions over whether it will be in handsets by the time users start transitioning,’ he conceded. ‘We may need back up ideas: dual-mode devices, and the supply framework ITT specifically mentions dual-mode, so dual TETRA and LTE devices is one option. The alternative (and there is one supplier out there with this) is a GSM-style handset – Bluetooth to the device and you then use GSM frequencies for device to device calls.’
EE’s Mansoor Hanif added that DMO will definitely happen, but it was a question of when the ecosystem gets there. German mobile operator Deutsche Telekom has undertaken some trials with mobile chipmaker Qualcomm. Hanif noted that some mobile network operators are not keen on DMO as they don’t like the idea of users going off their network.
‘DMO is a lot easier to do with TDD spectrum, and we now have some TDD spectrum, so it is easier for us to do,’ he said. ‘We are discussing with Home Office other ideas for TDD (which will happen first before FDD solutions). But I think you could include DMO in family pack tariffs, so it makes commercial sense for networks to implement it too.’
Measurement and validation of coverage to prove it meets the criteria
Addressing the issue of how the network coverage will be measured and validated, Whatson said: ‘We have traditionally used drive testing for this and I’m sure there will be an element of that with ESN, but with advances in technology we can make more use of end users and their devices. We can put an app on the device that reports back signal strength, coverage and quality in real time to the centre. There are other tools out there as well, and EE has its own tools too.’
EE’s Mansoor Hanif added that it will be using three tools: drive testing; the app-based solution (although this will only measure where end users actually go); and geolocation statistics from the network. ‘We triangulate those, but not quite in real time. However, again if no users travel along a particular road you can’t get any readings. But then you can use historical data.’
Richard Hewlett, Deputy Programme Director at the Home Office, emphasised: ‘Test and assurance is part of the contract with high level descriptions written in and we are working on the details now. But we need to ensure the lessons of the Airwave implementation are learnt. I don’t think driving the whole UK road network five times as happened then is the best way forward.’
Whatson concluded the session by saying: ‘We are trying to give the regions an idea of the coverage they can expect on ESN and is EE supporting us. But end users can also come in and we can discuss this. But as we start to get data back from coverage testing we’ll feed that back out as soon as possible.’
A further article focusing on the ESN – Transition session at British APCO event will be published later.