Operator QoS for Skype & Co.

Recently, Nokia has announced that they will integrate Skype into the Nokia N97. Reactions, obviously, have been mixed. But I think the trend is difficult to stop, if not on this device it will be on another or in another way entirely. Some network operators have responded by announcing that they are thinking about introducing special tariffs which would include VoIP. But there is one thing over the top VoIP (i.e. non-operator circuit switched voice) doesn't have today, and that is the possibility to ensure the quality of service (i.e. latency, delay and jitter) especially over the air interface.

However, with a bit of imagination it wouldn't be too difficult to set this up. Here's one example of how it could work: In tariffs that take VoIP into account, the network could establish a secondary PDP context (UMTS) or a dedicated bearer (LTE) when it detects IP traffic of VoIP applications. This prioritizes the voice IP packets over other IP packets in the data stream of the user and also over IP packets of other users. Most mobile network operators already have deep packet inspection devices in their networks for all sorts of things and these could easily do the job.

I think it's an interesting technical possibility, let's see if somebody picks it up and puts it into commercial reality.

4 thoughts on “Operator QoS for Skype & Co.”

  1. The other aspect would be emergency calls and location for Skype to be considered commercial and full fledged voice service. An operator might be willing to ensure QoS for OTT voice provided it makes business sense for them i.e, some revenue sharing with Skype.

  2. I always thought that for an operator point of view it wasn’t interesting to offer VoIP for a question of (radio) network efficiency. Instead, Skype offer to use circuit switch between an application on the terminal and a Skype server before going back to a “standard” Skype VoIP call.

  3. Hi,

    Thanks for commenting! I think Skype over CS is a temporary solution an specific to one operator. I’d be surprised if many would follow. Mobile operators don’t like VoIP today but with LTE at the latest, it’s difficult to avoid it.

    And there are lots of features to make it less of a waste of bandwidth such as IP header compression, better codecs and VoIP air interface scheduling.


  4. Hi Martin,
    interesting post, especially VoIP air interface scheduling.

    I will be amazed if operators actually use DPI to prioritise VoIP. Quite a departure from what’s happening today.

    From your experience (and instinct), what percentage of covered areas with HSPA can successfully deliver VoIP for mobile users?

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