Recently Safaricom announced that it had launched Safaricom VoLTE, a service meant to allow subscribers to make calls, not through the traditional CDMA or GPRS/GSM or even 3G voice protocols, but through VoIP (Voice over Internet Protocol) but this time the Internet is the 4G powered LTE protocol. LTE or Long Term Evolution is a technology still based on GSM/EDGE and UMTS/HSPA technologies albeit done in such a way that the data capacity is increased to a point it is considered 4G, but not as huge as True 4G which is WiMAX-Advanced. LTE although not as powerful as True 4G, has the ability to free up bandwidth if used for voice services, and this is one of the reasons Safaricom is pushing VoLTE for its voice services.
In addition to freeing up bandwidth (almost similar to the reasoning why people had to migrate to digital TV broadcasting), Safaricom is pushing VoLTE so that the voice quality transmitted to the the recipient is that of high definition. This is because VoLTE has a bigger bandwidth hence can accommodate more data and still leave room for other data services e.g. accessing YouTube while making that call. Consider it this way, with the traditional voice protocols, voice is normally compressed to about 8 kpbs which significantly lowers the voice quality. Compare that to a normal MP3 voice bitrate which is normally coded at 320 kbps, yet MP3 is not even the best codec for audio. With VoLTE therefore, Safaricom will be able to probably double the bitrate and transmit voice at 16 kpbs, which is still way below high definition but for a phone call it will be worthy to treat it as high definition.
The second bit that is also part of the increased bandwidth, and the fact that the communication will be over an Internet protocol, is the ability to make video calls. With the traditional technology, the only way one can make a video call is through over the top Apps such as Skype and WhatsApp, but if you have experienced these phone/video calls you know that they come with a lot of inconveniencing delays, where two people cannot talk back and forth without the first person having to wait up to half a second before the recipient gets the message, then responds. For telcos like Safaricom, the fact that one has to use WhatsApp in order to do voice calls deprives them of a revenue source. Of course the caller and the recipient are probably on Safaricom data, but data charges for such a call may not be as lucrative as per minute billing. Then again if the per minute billing will be more expensive than calling through WhatsApp, video chatters will probably still opt for WhatsApp video calls and not Safaricom’s VoLTE, and compromise on the delay. In addition to video calls, VoLTE will allow Safaricom to also offer file transfer, real time language translation, video voicemail and instant messaging, which collectively are called Rich Communications Services, or RCS.
The third advantage of VoLTE over the traditional voice protocol, and this is something I will test beginning today, is the speed at which calls can be set up. Right now on the traditional GSM network, it is taking Safaricom roughly half a second for the other phone to start ringing, so how faster will VoLTE connect calls? According to Neville Ray of T-Mobile, the speed at which VoLTE connects call can be twice as fast as non-VoLTE call setups, which means within a quarter a second of trying to make that call, the call shall have gone through. This I don’t think is so much of an advantage. Sometimes, which happens more often than not, you may want to call someone, but instead of clicking on his contact, you click on the contact of someone else, someone you rather never call. Once the screen starts showing that the phone is calling the wrong person, you rush to end that call. In most instances, the call doesn’t go through. With VoLTE however it means that such mistakes will be punished by the network sending a missed call signal to that person, who might call you, and you will always have to have words ready to explain how on earth you flashed him.
I’m not sure about this part but Safaricom could be pushing VOLTE because researchers have demonstrated that a phone’s battery life lasts a bit longer when used for VoLTE as compared to when used over traditional voice protocols. My lack of surety stems from the fact that when phone data is switched off, the battery can last as twice as long. Probably when the GSM/GPRS network can be switched off but the data (LTE in this case) remains on, the the battery can last a little bit longer than when data is switched off but GSM network is still on. This is something I need to test too.
One last advantage of VoLTE over 2G and why Safaricom is Pushing VoLTE, and this is again associated with the increased bandwidth, is the fact that an operator like Safaricom can integrate noise reducing protocols within the data packet. This will mean that someone can still go ahead to make a phone call despite being in somewhat a noisy background. Again, this is something that I will have to test. Of the tests that I have promised to carry out, which includes tests on how fast a call connects, the high definition voice call, tests on phone’s battery life, and background noise cancellation, look out for my next week’s article to be titled “Personal Experience with Safaricom VoLTE Protocol”.