VoIP’s problem with Wifi

A couple of months ago I’ve been reporting about my experiences with the UTStarCom F1000G Wifi VoIP phone. It went back into the box basically because the software was too unstable. Another reason I didn’t like the phone at the time was that the Wifi reception of the phone was not very strong and voice quality suffered when only two walls were between the access point and the phone. At the time I thought this issue might be related to this type of phone only. Now one of my friends reports that he has the same problem with Nokia E-series phone he tried out. While stability was not the issue, voice quality degrades pretty quickly when moving away from the access point. He also came to the conclusion that the range is no match to those of DECT cordless phones. Looks like good Wifi antennas have not yet found their way into small form factor phones. However, I am afraid that’s a necessity to make VoIP over Wifi work.

6 thoughts on “VoIP’s problem with Wifi”

  1. Martin,

    I’m not sure I agree with your friends experience on the E series. I currently have a range of E series devices running over Wifi integrating to Call Manager via the call connect client for Cisco. Every single colleague I have demonstrated this too has been surprised by the quality and reception. I think the complexity here comes in the wireless architecture deployed. I’m not sure the Device E series or other can be blamed for a poorly thought out congested network architecture..

    I’m meeting with Cisco and Nokia over the next few weeks and will dig further into where they see the issues and shortfalls….


  2. Hi Scot,

    I agree than in an office space, you can install Wifi AP’s at proper locations and thus VoIP over Wifi should be o.k.

    At home on the other hand most people do not do a lot of network engineering. They just put the Wifi access point somewhere and expect the phone to work two rooms down the corridor and one floor below as well. That’s where the trouble starts. DECT does that easily.


  3. I recently spoke to a Qualcomm engineer, who pointed out that the best household setup was multiple access points cabled to a switch, because your data rate increases the closer you are to an access point, and you will be less likely to interfere with your neighbors’ networks.

    Of course most people use a wireless access point in order to not use cables…

  4. Hi Chris,

    thanks for commenting. I think not many would be happy to have several access points at home when Dect phones work with only one. But I guess antenna
    technology will eventually improve. Until them I will live with my Sip to Dect phone.


  5. Yet another topic where it would be good to understand more about how devices are built. I would assume that it is not totally fair to compare a DECT phone with a general multiband mobile phone with respect to receiving capabilities. The DECT phone has 1 antenna that is specifically adjusted to the receiver and it operates in just one frequency band (1880 – 1900 MHz in Europe). Plus, DECT phones offer relatively much room to place the antenna.
    The Mobile phone has three or more receiving ends: Multiband GSM, UMTS, WLAN, bluetooth, GPS. All probably needing one or more antennas that have to work over a much broader spectrum and are therefore more difficult to atune to the different receivers. And don’t they interfere with each other? I believe bluetooth and WLAN are operating both in the 2.4 GHz spectrum, don’t they?

    Hm. Any phone RF specialist here?

  6. Hi Jens,

    Thanks again for the comment. I agree with you, from a technical point of view a DECT phone and a cellular phone with Wifi and a VOIP client can’t be compared.

    The user, however, doesn’t care. If his cellular-wifi-voip client phone doesn’t work as well as his DECT phone it’s a no go for him. But I think wifi technology and antennas still have some room for improvment so I think we will see phones in the reasonable future that will work well.


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