I find that I’m repeating myself more and more. It’s not senility, it’s the line. In the 20 years that I’ve been using mobile phones, call quality has been in steady decline. It’s particularly noticeable on international audio-conferences with calling parties on multiple end points.
While PSTN call quality has remained static, and Skype brought an unexpected crispness to voice conversation (when you have a good connection and no jitter), mobile calling regularly frustrates, despite billions of dollars being invested in mobile networks over the last two decades to expand coverage and capacity.
It is perhaps surprising that you can get differentiated levels of service for almost anything except voice. Even if you wanted to, you’ve not been able to pay for premium quality mobile calls. That’s partly because the mobile industry has long seen voice as table-stakes. Bundles of minutes got larger and larger until the bucket was so large it couldn’t be consumed in a year, never mind a month. Revenue growth focus switched to SMS and then mobile broadband, and voice was simply seen as something to give away.
And therein lays the problem: the mobile network does not discriminate. Bandwidth hogs undermine the network performance within a cell. This report claims that just 1% of mobile subscribers are using up 50% of 3G downloading capacity. It’s even worse with LTE, where 0.1% of subscribers are using up half of all available downlink. Pity you if you are trying to access an app when you are in close proximity to one of those users. The operators have been trying to in-fill the network to cope with these spikes in demand. While voice and data connections are typically on different spectrum bands, investment has been ploughed into the latter at the expense of the former.
And it would not be fair to just blame operators for a lack of investment in voice. A study in Denmark found that call quality varies by a factor of 10 based on the handset manufacturer. It even matters how you hold your phone, particularly the iPhone 4S, which offers better call quality than the iPhone 5, according to reports. Hold it the wrong way though and you could be talking to yourself.
industry drive towards high definition voice
Operators and handset manufacturers are attempting to resolve the issue of poor quality calls with HD Voice. This is a wideband codec based on G.722, which itself has been around since the eighties. In HD Voice, a much wider range of sound is sampled, adding depth and nuance, while reducing the bandwidth requirement to 32kbps. There is a raft of handsets supporting HD Voice and 93 operators have launched HD Voice capabilities in 66 countries.
Even if you have a HD Voice handset, you may never have noticed that you have had an HD call. Your operator will need to support it, and so will the other party’s handset and their operator. And just because the operator supports it, that doesn’t mean that all the base stations in their network do. And it is still subject to coverage and capacity issues, so consequently not many operators are promoting the capability just yet.
This may soon change as HD Voice handsets and networks reach a critical mass.
In a recent report Mobile Call Quality: Does Better Really Matter, Heavy Reading analyst Tim Kridel argues that when call quality sounds better, people talk longer, up to 45% longer. And the longer they talk, the more they spend on call minutes. And this is why many operators are investing hundreds of millions of dollars in supporting HD Voice. They won’t charge extra for improved call quality, but they can charge for longer calls. Plus, call quality is a major reason for customer churn. A survey by Orange of its HD Voice customers found that 86% would use it as a criterion for their next purchase.
This is perhaps why Everything Everywhere (part owned by Orange) is investing over €300 million in HD Voice and voice-over-LTE (VoLTE) to improve voice quality on its UK network.
VoLTE is the next step in improving voice quality both for the operator and user. Currently, today’s 4G LTE subscribers are not benefiting from 4G voice. Their 4G handset will step down to 3G or 2G to make the circuit-switched voice call, and so encountering the same problems that all other subscribers have with voice calls -– patchy coverage and cramped spectrum.
VoLTE packetizes voice is a similar way to VoIP on fixed networks. It uses up less spectrum than circuit switching and can either be HD or standard (so that you can call any other phone). But VoLTE is a very complicated technology, bogged down in compatibilities issues, which is why there are only a handful of networks currently offering it, including Metro PCS in the US, and SK Telecom in South Korea. AT&T has recently indicated that will it soon offer VoLTE in the US in 2014, and it will combine it with HD Voice.
Personally, I’m looking forward to it. I spend a lot of my working life on conference bridges. The more of us with devices and operators supporting HD Voice, the better. I might be able to stop repeating myself. I said, I….
image © Faysal Farhan - Fotolia.com
I've been writing about technology for nearly 20 years, including editing industry magazines Connect and Communications International. In 2002 I co-founded Futurity Media with Anthony Plewes. My focus in Futurity Media is in emerging technologies, social media and future gazing. As a graduate of philosophy & science, I have studied futurology & foresight to the post-grad level.