The audio quality of mobile phone calls often leaves a lot to be desired. On GSM only, calls are a tinny low-bitrate affair and although 3G has gone some way to increasing the quality of calls, there’s certainly some room for improvement; maybe HD can help.

HD is a buzz word that’s banded about with gusto interference to video, audio and now thanks to Orange, phone calls. OK, we’re not talking real ‘HD’ here, the thought of HD phone calls that carry with them the same quality and timbre of HD audio like Dolby TruHD and DTS MA is quite simply a pipe-dream, but to my mind any improvement to call quality is a good thing. Orange are quoted as saying the difference in call quality should make it ‘sound like the caller is in the same room’.To put it in perspective, the difference is said to be as big as the quality difference between medium wave and FM radio. Now that’s a promise I expect them to uphold.

The problem is that HD phone calls rely heavily on the 3G data network, something that in the case of networks like O2 and AT&T are already a little stretched. The UK’s third largest network, Orange, has been successfully testing HD calling over their Moldovan network without capacity issues and hopes to roll out HD calls to it’s UK network in 2010. There is one slight snag in that your current phone is not going to be compatible with HD calling, but Orange said that it’ll have HD call capable phones on sale to accompany the network’s HD calling activation. Orange is set to complete it’s merger with T-mobile in the UK in the next few months, which will catapult it from third after O2 and Vodafone, to the largest UK carrier, lets just hope that it doesn’t suffer the same fate of O2′s network over capacities. Maybe we’ll see an HD calling capable iPhone launch in July this year now that it’s available on multiple networks in the UK. Let’s hope for Orange’s sake that it’s network can handle the extra load created by all these data heavy services.