Voice calling, VoLTE and RCG. Why you might not be able to make an emergency call from your mobile phone this summer.

While we know fixed line broadband in New Zealand is now awesome with Gigabit capable fibre to over 80% of premises that has been rolled out over the past 10 years, in recent years our mobile space has not seen the same levels of change. While 2degrees have been busy expanding their own network to avoid relying on roaming on Vodafone's network, we have seem very little in the way of major coverage expansion from Vodafone and Spark.

The harsh reality is that once both networks reached around ~98% coverage of the NZ population, expansion to cover new areas became very costly. Providing sites to cover very small areas of population don't come cheap - whether it was the lack of suitable sites, construction costs if suitable sites were available, lack of fibre backhaul, or remote locations that meant high capacity microwave links for backhaul were incredibly expensive.

Since the National government announced the funding of the Ultra Fast Broadband (UFB) fibre network in 2009, successive National and Labour governments have spent up big on connectivity in New Zealand, with expansions of the UFB fibre network to many smaller towns, and significant investments into rural connectivity for areas where fibre is simply not cost effective to deploy.

In 2017 the Rural Connectivity Group (RCG) was formed to fast track rural mobile phone and mobile broadband connectivity into areas without coverage. The RCG is a joint venture between Spark, 2degrees and Vodafone that plans to build a minimum of 400 new mobile sites between 2018 and 2023 to improve mobile phone coverage in rural areas, and deliver wireless broadband to many areas that currently have poor (or often no) other broadband options. The RCG is funded by all three networks as well as government funding through their Rural Broadband Inititive (RBI) program, as well as their Mobile Black Spot Fund (MBSF).

What makes the RCG network unique is that it's built using Nokia's Multi Operator Core Network (MOCN) technology. Each new cellsite contains Nokia MOCN equipment that allows all three networks to provide service and share spectrum rather than each network operator having to provide their own equipment and share a tower. This means the cost of deploying these new sites is significantly cheaper than each network having to build their own site. It really is the perfect solution to enable sharing of costs in low use or hard to reach rural areas.

When the RCG network was designed it was decided that it would be a 4G/LTE only network using 700MHz spectrum. Some RCG sites on major state highways that have been funded as part of the MBSF also have a 3G network using 2100MHz spectrum. Here in New Zealand Spark, 2degrees and Vodafone operate both 3G and 4G/LTE networks, while Vodafone has both 3G and 4G/LTE as well as still maintaining a 2G GSM network.  

When a mobile device is connected to a 2G or 3G network, voice calls are made using circuit switching. When 4G/LTE was designed and the focus moved to it being a pure IP based radio layer with no circuit switched capability, the solution for voice calling was for devices to drop back to a 2G or 3G network to make a voice calls.

Up until late 2019 when VoLTE (Voice over LTE) was officially launched in New Zealand, every time you made a voice call on a mobile in New Zealand your handset dropped back from 4G/LTE to 3G or 2G to setup the voice call. If you have a non VoLTE capable device your calls will still continue to fall back to a 3G or 2G network for calling. VoLTE is simply a Voice over IP (VoIP) solution which carries voice calls as packets of data over the 4G/LTE network.

One of the key aspects of deploying a 4G/LTE only network for the RCG expansion was that it would mean all three networks would be forced to deploy VoLTE upgrades to their network to offer a voice solution on 4G/LTE only sites. Without VoLTE nobody would be able to make a voice call on any site that did not have 3G.  

While VoLTE has been around since the first commercial launch in 2012, it is safe to say the technology has been fraught with issues. Due to minor differences in VoLTE deployments and interoperability, for a handset to be able to use VoLTE it needs to be approved by the network operator, and the correct settings pushed out to the handset. While 250+ mobile networks around the world have deployed VoLTE, it is still far from being a perfect solution. There is also currently no large scale VoLTE roaming, meaning that even if you have a VoLTE handset and use VoLTE on your home network, if you roam overseas you will find voice calls are carried over 3G or 2G networks.  

While VoLTE capable handsets have been sold here for several years, the reality is that out of the roughly 6 million mobile connections in NZ there could easily be 50% of those devices that do not support VoLTE. I asked one of the networks in NZ if they could provide a total number of VoLTE capable devices but was told that information was commercially sensitive.

There are potentially a couple of million mobile handsets in the country that don't support VoLTE which means they're unable to make a voice call (including 111 emergency calls) while connected to a 4G/LTE only RCG site. Anybody roaming in New Zealand on a foreign mobile handset would also be unable to make a voice call or emergency call even if their phone supported VoLTE due to the lack of VoLTE roaming.

What's surprising is that not every handset being sold in New Zealand right now is VoLTE capable, with my estimate being that probably only 75% of new handsets sold are VoLTE capable. While Apple have had VoLTE support on every iPhone from the iPhone 6 onwards, and Samsung offer VoLTE support on the vast majority of recent handsets, many other manufacturers have mixed offerings. It should be assumed that any imported handset sold in NZ or imported by an individual (with the exception of Apple devices) will not have VoLTE support on any network in NZ, even if the handset says it is VoLTE capable.

While all of this was well known in the industry, as well as by MBIE who were responsible for funding the RCG project, it's an issue that seems to have largely escaped the notice of the general public. It's rather ironic that MBIE are on one hand imposing very strict rules on fixed line telecommunications providers when it comes to ensuring availability of 111 calling during power outages as we move away from copper landlines to fibre and fixed wireless alternatives that use VoIP, yet they seem either oblivious or simply ignorant of the fact somebody walking into a store today and buying a new mobile handset could be buying one that is incapable of making voice calls (or more importantly emergency calls) in many of our remote areas which are now receiving mobile coverage as part of the RCG project.

If you look on the websites of Vodafone, Spark or 2degrees it's not easy to tell what handsets are and are not VoLTE capable. There is no clear warning on their websites that non VoLTE handsets may not be able to make calls in some parts of the country. Likewise there are no big red stickers on the boxes of phones in retail stores warning of this issue.

Here on Geekzone there have been an increasing number of posts in recent months from people who have been unable to make voice calls while attached to RCG sites, and for the people affected by this understanding why this was happening has clearly been confusing with a lack of clear communication from providers. None of our mobile carriers nor MVNO operators seem to have made any serious attempts to warn customers of this limitation.

On Tuesday industry organisation the NZ Telecommunications Forum published a new post on their website explaining about VoLTE on RCG sites. While it's great that this issue is finally being raised, it all seems a case of wondering why this issue is only just now being raised by the industry.

Sometimes us techy people just assume the general public is as smart as us and understand complex scenarios. VoLTE is one example where that's not the case. We've all known about this issue but don't seem to have done a lot to tell the general public about it.

The fact a significant percentage of the population with older handsets are unable to make voice calls on RCG sites, and could find themselves being unable to make a 111 emergency call if needed as they're unaware of this issue is simply not good enough. MBIE, the TCF, Spark, Vodafone and 2degrees along with every MVNO who provides molbile services on their networks needs to be doing a lot more to educate the public about RCG sites and VoLTE, and make people aware of voice calling limitations.

It's about time that every new handset sold in the country should be VoLTE capable, even if this means low cost handset that don't support VoLTE disappear from the market. Until we reach this point every handset sold that is not VoLTE capable should feature a sticker on the box warning of the issues.

To do nothing simply isn't good enough...

 

Other related posts:
Is the TCF mobile blacklist fuelling New Zealand’s latest crime fad?
Spark Paging network shutdown – the event nobody cares about? Not quite.
UFB voice, power cuts, copper invincibility and mainstream media FUD.