Realising the potential of Fixed Wireless Access

THE HISTORIC PROMISE OF FWA

Fixed Wireless Access (FWA) has often been positioned as the principal alternative to wired infrastructure in rural areas, as a means to provide to rural communities the same level of telecommunications services enjoyed by their urban counterparts.

Removing the dependence on a “copper drop” that implements the first mile between the customer and the local exchange has a number of advantages.

Deploying that copper drop is expensive. The actual copper itself has value, but there is also significant cost involved in the deployment of the wired infrastructure from the service provider to the customer. Take that out of the equation, replace with wireless and in theory it should be significantly cheaper to deploy.

It should be quicker to deploy too. Whilst each customer needs to be individually served by wired infrastructure, a wireless base station promises coverage to all customers which can be reached by its wireless signal.

That wired infrastructure also needs maintenance. Historically, maintenance of the copper first mile has been an expensive and time intensive activity, frequently requiring the dispatch of an engineer. Wired infrastructure can be broken by intrusive activities such as road works, or building an extension to your house. It degrades with time, water ingress is a concern.

None of these are concerns for wireless. The wireless connection between a base station has to be planned of course and the base station itself must be maintained, but once implemented, all of those wireless connections between the base station and the customer will be much less likely to go wrong and require maintenance.

Commercially, when breaking free of the highly regulated wired infrastructure, you have something of a blank canvas, to position differentiated services and innovative tariffing.

Whilst satellite is ubiquitous and has many well proven, positive deployments over the years, it is not universally deployed in rural areas as the panacea to lack of wired infrastructure. In comparison, FWA is cheaper and offers a more predictable level of performance, with factors such as latency being particularly in its favour.

So far, so good. However, although FWA has been deployed in many markets, it is yet to realise its full potential. Why is this case and what might be happening to kick start the interest in and take up of FWA ?

HISTORIC FAILINGS

As with all wireless technologies, the availability of spectrum is the first hurdle. Development of new base stations and CPE is an expensive activity and vendors want to develop product with broad application. The global availability of spectrum for delivery of rural broadband has been a challenge, which until recently has had no broadly accepted solution.

The availability of suitable technology has also been an issue. Over the years, a number of FWA products have been created and have been deployed in markets around the world. But frequently, they have been based on proprietary wireless protocols, mobile derivatives, or have been adapted from enterprise grade WiFi products.

Proprietary solutions can be high quality and can deliver an excellent service, but this will come at a price. Unable to reach the volumes of standard solutions, they are more expensive to supply and with less access to trained operational personnel, they are also more expensive to deploy and operate.

One of the great hopes for a broadly accepted wireless access standard was WiMAX and in particular, the fixed variant of this. Standardised through IEEE802.16d and IEEE802.16e, WiMAX was heavily backed by a number of organisations in the USA in particular, but was pitched into battle with competing standards and ultimately lost out, due to lack of access to harmonised spectrum and the global adoption of 3GPP standards and technology. Although deployed as an FWA solution, particularly in areas such as east Europe, fixed WiMAX networks around the world are being decommissioned and replaced with other solutions.

There was also the issue of purpose. Legacy FWA products have tended to be seen not just as alternatives to fixed lines, but were also judged on their ability to deliver voice. Universal Service Obligations come from the need to give rural users access to a voice service and solutions were created to be an effective means of delivering voice. Not just any voice either. It had to be something which would meet the very high standards of the fixed, circuit switched network, with Mean Opinion Scores, regulatory requirements and high customer expectations. The bar was raised high and yet the reward for delivering this impressive voice capability was being constantly reduced.

With the focus on providing a premium voice service and the need to implement in less accessible, unharmonised areas of the radio spectrum, FWA shied away from the biggest technical, commercial and regulatory advantage available to any wireless solution – the 3GPP mobile ecosystem.

TODAY’S FWA SOLUTION

The passage of time has radically changed the telecommunications landscape. The fixed network carries substantially fewer landline voice calls – in the UK, such calls have halved in five years. At the same time, mobile voice calls and both fixed and mobile data usage have risen and there is no reason to believe that this will not continue to be the case for years to come.

With such a level of mobile usage and user behaviour shifting solidly to “data first”, the focus on voice quality comparisons has undeniably diminished. Customers have so many means of communication at their disposal that, where there is a need to be in contact, there is almost always a way of achieving it and technical advances, allied to competitive availability of sophisticated mobile apps, have greatly improved the quality of this contact.

The rural requirement now is for a wireless product which is an effective data pipe and which can be delivered in standard spectrum. The need for delivery of voice is still there of course, but with the overwhelming shift towards data usage, including the use of applications supporting alternatives to “standard service provider” voice, there is no longer the need for premium quality voice which replicates the legacy fixed line service.

USING 4G AND 5G FOR FWA

All in all, the rural requirement could not be a better fit for the world’s most successful wireless access standard – 4G and its unstoppable consequence, 5G.

The 4G standard itself was created specifically for mass deployment of wireless data services and, of course, it has been globally adopted. It has spawned open ecosystems providing access to a multitude of mobile applications from readily accessible app stores. The flat architecture of the 4G network greatly facilitates its deployment as a fixed rural access network, an advantage retained by 5G.

Availability of spectrum is a challenge for any wireless product, but products based on 4G and 5G benefit from the global 3GPP ecosystem, including the ability to influence regulators and lobby governments. Whilst super national organisations such as the EU do not support the availability of harmonised spectrum for WiMAX, the 3GPP community pushes against an open door.

4G and 5G benefit not just from the large number of bands allocated for and used by mobile applications, but from bands suitable for and available to FWA.

Undoubtedly, the most promising spectrum can be found in the area between 3.4GHz and 3.8GHz. Frequently used by WiMAX, it is now seen as the most promising band for opening up to new competition, often on an unlicensed, or lightly licensed basis, for encouraging the deployment of rural FWA networks.

Amongst the leaders trailblazing in the release of this spectrum, in the USA, the FCC’s completion of a long process of consultation has resulted in the release of the CBRS spectrum (3550MHz to 3700MHz), accessible to new entrants under the OnGo brand. Additional consultations are at varying stages of completion in a number of other countries, including several in Europe. The result of this growing process of consultation and release of spectrum will be a broadly harmonised TDD band, available on an unlicensed, or lightly licensed basis to innovative new service providers, which meets all of the requirements for 4G and 5G based FWA networks in rural areas.

THE RURAL FWA CORE NETWORK

The great advantage of any rural FWA solution based on 4G and 5G is that it builds upon an ecosystem supported by well established vendors, populated with thousands of competent and experienced professionals, responsible for a vast range of standards compliant products.

As with any 4G and 5G network, there is a need to deploy an Enhanced Packet Core to interface new generation 4G and 5G FWA base stations (eNodeBs) to the internet and the rest of the world beyond.

Historically, EPCs have been created to serve the needs of large national Mobile Network Operators (MNO). The requirements of rural FWA networks are quite different. Rural FWA networks are much smaller and the customers of such networks are dispersed between small communities, often in remote locations.

There are different functionality requirements as well. The EPCs deployed in mobile networks are complex and feature rich, supporting complex roaming capabilities. Rural FWA networks are created for quite a simple residential broadband purpose and need support neither inbound nor outbound roaming.

There are also requirements specific to geographically remote rural areas. For example, there is often a requirement to locate EPC functionality to the edge of the network, within or adjacent to the rural base station. Advantages in doing this include the possibility of remotely offloading data and implementing services at the edge of the network.

FWA networks must still support state of the art functionality. For example, IOT is likely to be an interest in rural FWA network, rural communities still have enterprises.

Created specifically to address mobile applications which can not be cost effectively served by the older generations of EPC targetting large MNOs, AttoCore products such as AttoEPC are perfect for this purpose.

A dedicated focus on 4G and 5G means that a vast quantity of legacy functionality harking back to the circuit switching days of 2G and 3G is not present. This makes for a smaller, less complex executable Such characteristics allow the product to be embedded directly in the radio chip used by these new generation FWA base stations. With less to go wrong and a development methodology based on continuous testing of all functionality, there is an emphasis on quality, a major requirement for any embedded system. Unlike data centre based applications, it is notoriously difficult to fix software embedded in multiple instantiations of hardware, distributed over a wide area, often in difficult to access areas. Software in a data centre can be easily patched and upgraded, but for embedded systems, it is much better to have quality built in by design, by careful implementation and by rigorous system testing.

The product is implemented to exploit multi threaded operation, a technique used by chip manufacturers including Marvell (and specifically found in their former Cavium chips), which results in significantly increased capacity, in comparison with legacy “multi process” based approaches. Running on top of the Linux operating system, with no specific hardware dependencies also allows the AttoCore software to be deployed in data centres, or in the Cloud, on COTS servers. AttoCore software is implemented as virtual network functions, which can be run on bare metal, in virtual machines, or can be containerised.

Many FWA applications are implemented by smaller service providers, with less access to expertise and in some cases originating from backgrounds outside of the telecoms industry. Ease of use is a major requirement and a feature of all AttoCore products.

Product pricing is also geared to the needs of smaller networks. AttoCore does not have to support a global product management structure reflecting the requirements of global MNO customers and so can craft pricing solutions which are fit for purpose.

An open approach is also required. AttoCore supplies its product in the expectation that it will work with the products of other suppliers with the same open approach.

AttoCore’s AttoEPC is already deployed in rural Fixed Wireless Access applications. A showcase project – Chalke Mobile, located in the rural county of Hampshire in the UK – has been used to pioneer neutral host models with the UK’s MNOs. The evidence of that deployment strongly backs up AttoCore’s assertion that AttoEPC is the right EPC for rural FWA networks implemented on CBRS like principals.

TOWARDS THE RURAL VISION

In many countries, the “digital divide” is an unfortunate reality. Rural communities do not benefit from the same telecommunications services as those in urban areas. Impact is felt in so many areas :

  • reduced opportunities for home workers
  • inadequate access to education materials for school children
  • diminished competitiveness for rural enterprises
  • lack of access to online public services for the elderly and less mobile

Fixed Wireless Access has always promised to be the means of bridging this digital divide. Now, with the availability of new unlicensed and light licensed spectrum (specifically CBRS and more generally 3.4GHz – 3.8GHz), with the availability of fit for purpose 4G and 5G technologies and products, with a multiplicity of existing and new service providers looking to exploit the opportunity, together with an active 3GPP ecosystem willing to supply them, the prospects of this happening have never seemed so real.

steve.coppins@attocore.com

Meet AttoCore at MWC Barcelona, February 24th-27th, Hall 7, Stand 7A11-7