From the beginning of 1st Generation mobile systems, access network architecture has changed very little. That’s not to say that we have not seen dramatic changes to the technologies deployed in the access networks through the generations and in the associated back haul. The need for backward compatibility has meant that we have tended to mix-and-match 2G, 3G, and LTE to create a one-hat-fits-all wide area macro access network to serve all user cases. It’s worked fine so far but the future user cases and business models emerging in the wireless world mean that now we to be much more efficient in using the access technology that best suits the explicit market needs and those that are optimised around different products and user cases. Fit for purpose access technologies are emerging and the trick for service providers of all types is now to produce a strategy that encompasses the right solutions for right user cases and business plans. In this hot topic, we explore the options and the opportunities that lay ahead as the revolution in the access network takes shape. Decision time is looming.
The access network has always been and will continue to be the biggest demand on capital expenditure for wireless operators. The breadth and depth of radio coverage, quality of service, and capacity all have major implications on capital expenditure. If we also factor in spectrum charges on top of this, we begin to see just why the access network should be commanding so much attention amongst mobile operators. As any CTO or CFO will tell you, it’s also like painting the Forth Bridge, it’s never ending as new technology is always forcing its way onto the technology road maps. The new technology also helps to some degree with the challenging economics. If it’s doing its job properly, technology should be driving down unit costs, improving the quality of service, allowing better in-building coverage, and increasing coverage reach. This is the mantra we hear from the vendors, pushing hard on the new technology and certainly it is the basis by which MNOs make their business cases work. Nonetheless, it still all comes with a large price tag and quite often requiring new investment even before the last technology has reached pay back. Yes indeed, the access network is the major challenge facing MNOs and that is not going to change in the future.
Access networks are evolving fast. In fact, we think it’s more revolutionary then evolutionary. Attributes such as SDN, MEC, NFV, and Cloud RAN are all challenging conventional architectures for the access network and we deal with these in our hot topic ‘Network Evolution’ (add link). Here we wanted to look at the radio interfaces in the access technologies, LTE (E-UTRAN), 5G, License-Assisted Access (LAA), LTE-WLAN Aggregation (LWA), and LTE WLAN Radio Level Integration with IPsec Tunnel (LWIP) and of course public and private Wi-Fi and then work on how MNOs should formulate their strategy. We think that this needs to happen ahead of 5G spectrum auctions because for the first time, MNOs need to be thinking not just about the licensed spectrum being auctioned but also about how this is complimented with other access technologies to provide the most cost efficient and service centric access network.
There is a large consensus that says mobile data traffic will increase dramatically world-wide between now and 2020 and the growth will be predominantly driven by developed markets. At Azenby we like to do a bit of polling of all the predictions we see published and our reading tells us the top end of the growth range is that mobile data will increase tenfold during this period and the more conservative view is that it will increase by ‘only’ fivefold. Perhaps something in the middle is a good hedge bet. If we start to prepare for the mid-range of growth predictions, that would mean something like 25 Exabyte of data per month. This where the need for deploying unlicensed spectrum arises because it is hard to see how conventional cellular over licensed spectrum can economically support that level of traffic. If it looks like being impossible for MNOs not to embrace unlicensed spectrum, then in doing so why not look at other opportunities this can bring such as addressing some of the IoT market and new and existing verticals?
Once converted to unlicensed spectrum we see license-exempt spectrum used for Wi-Fi, LAA, LWA and LWIP as a catalyst for innovation. The opportunity for MNOs include benefits such as no spectrum charges, increased capacity, and lower unit costs for a lot of user cases.
The Azenby Approach
The access network as we have conventionally defined it has been the preserve of the MNO. Things are changing fast though and now MVNOs increasingly look to see how gaining a degree of self-managed access can help reduce their host network charges and broadband service providers are looking at LTE as a ‘last mile’ connection. Some MVNOs are already in the market with a Wi-Fi first approach and this has the potential to shake up the mobile industry. At Azenby we don’t believe that there is any such thing as a standard approach to the access network revolution. There is no one-hat-fits-all scenario anymore and the right strategy will depend very much on the nature of the business involved, they services being taken to the market and starting point.
High license spectrum charges, or spectrum licensing conditions, have had a big impact on MNOs business cases ever since the first painful 3G auctions of the early 2000’s. Some solace is taken from the fact that these spectrum conditions have created a very high barrier to entry for new incumbents. The desire for governments and regulators to extract large sums of money for spectrum for their own treasury has not been well balanced against their desire to also increase market competition but that’s a story for another day. Notwithstanding that high spectrum charges have restricted competition, MNOs know that meeting future capacity demands with expensive licensed spectrum alone is not sustainable and the need to use unlicensed spectrum must come into the mix if the economics of the business are to stack up.
A real topic for debate at MWC2017 was around the user cases and services that 5G will bring. For those seeking answers to these questions, the wait might be long one. That doesn’t mean that operators can’t look now to what else 5G should bring them. Lower unit costs, the ability to leverage scale through convergence. Critical to these is the access network and not just because as we pointed out at the beginning, its where most of the capital expenditure goes.
If 5G lives up to our expectations will see for the first time a true combination of licensed and unlicensed technologies but some still believe that license spectrum will dominate the mix. Operators are certainly keener than others in the industry to see a greater use of unlicensed spectrum.
At Azenby we work closely with our clients becoming part of the team cracking today’s challenges and delivery concrete results. We understand that every customer is different and every business plan has its own unique features so we don’t bring shrink wrapped solutions from other parties to the table. We tailor strategies to fit the specific business needs.
We see the call to action as being compelling and the need to have some answers in place before 5G spectrum auctions occur as a necessity. We know we are preaching to the converted here as our ear-to-the-ground around the MNO world suggests to us that the clear majority of operators believe that 5G standardisation will address the multi access network opportunities but some have concerns over the timescales. Must operators seem to be hedging bets on whether they will have deployed 5G by 2020 but we see others, mainly in Asia, as being very aggressive and wanting to beat those dates. Standardisation is undoubtedly the critical path item. Followed closely by our age-old problem of the availability of devices.
The starting point needs to be in understanding all the options and then figuring out which technology is the most suitable for products and services.
LTE-WLAN Aggregation (LWA) – Aggregate both licensed LTE and unlicensed Wi-Fi to increase performance without the need to modify already deployed WLAN infrastructure. This allows dual connectivity solutions to be deployed.
Licensed Assisted Access (LAA) – Most crucial to MNOs to deliver network quality and performance improvements. This LTE feature leverages the 5 GHz unlicensed band in combination with licensed spectrum and can utilise Carrier Aggregation (CA) solutions to aggregate both licensed and unlicensed LTE paths. This allows the MNO better quality control over unlicensed path(s) by using existing LTE control functions.
LTE WLAN Radio Level Integration with IPsec Tunnel (LWIP) – Being developed as more user operator friendly way of achieving concurrence between LTE and WLAN as the Gateway needed in UTRAN/WLAN deployments is no longer required.
LWA and LWIP can be combined which means MNOs can form partnerships with Wi-Fi Operators in non-co-located deployments
LTE and WLAN access remain the fundamental building block of course but the options beginning to open up to Service Providers and Operators to better tailor access networks to meet business requirements and optimise service delivery means the old one-hat-fits-all access network will be outdated.
IoT Access Options – We will not deal here with specific access technologies for IoT such as LTE NB, Bluetooth Smart, Wi-Fi, Zigbee, Neul, Sigfox, LoRa etc. as this is another hot topic in its’ own right!
Case studies
Have we got a case study to show you on the access network revolution? Well nobody has. We are talking about what is to come here but it’s important to be involved early and shape the technology enhancements.
We have done a lot of work on mobile access systems in our time! We have been involved in the world’s first 1800 network and at that time our back-haul was 90% self-provided on our microwave transmission network. We progressed through the back haul evolutionary chain to today’s sophisticated Ethernet back haul networks. We were heavily involved in the first major active RAN share deal and have worked with clients all over the world on access network cost reduction and performance improvements.
Integrating Unlicensed Spectrum into the MNO’s RAN and EPC Technology and the development of LTE in unlicensed spectrum bands is very much in its early days still. One of the key challenges will be dealing with issues like interworking with Carrier Wi-Fi. This together with the emergence of user cases will be an industry focus for the coming months.
If we can help you put together a plan for making the access network revolution work for you than why not get in touch.