+1
We've just been through the same with a couple of new accommodation blocks where the construction was changed half way through the process to precast, re-enforced, concrete with bathroom "pods" on corridor walls.
The build saved some cash but we wouldn't commit to a wireless spec until we'd tested both in corridor and room based AP's. We ended up with room based AP's as the construction created a really unpredictable RF environment.
Will
-----Original Message-----
From: Wireless Issues in the JANET community [mailto:[log in to unmask]] On Behalf Of Scott Armitage
Sent: 11 May 2017 16:21
To: [log in to unmask]
Subject: Re: Frequent Disconnections from Wireless
> On 11 May 2017, at 15:47, Jim Higham <[log in to unmask]> wrote:
>
> Dear all
>
> A number of students are experiencing frequent disconnections from Wifi (both eduroam and our Wifi Guest services are affected – we don’t offer any other SSIDs) at times in one of our accommodation blocks. The construction of the block is unusual in that it has many internal metal lined walls, which is not great! The students report that they don’t get the issue around campus, and it generally affects more than one device for each student (ruling out specific device issues).
>
> My questions are:
>
> 1) Have you had any similar issues at your site?
Yes in new accommodation blocks which were constructed about 6 years ago. The contractions of the building is such that walls are reinforced concrete and modern building regulations mean inevitably Kingspan / Celotex insulation is installed which isn’t very wifi friendly. The shower cubicles between the room and the corridor are particularly efficient at attenuating RF.
> 2) Have you had any success getting an independent survey done to help troubleshoot, and if so, have their recommendations worked?
We have surveyed ourselves and based on what we saw we have opted to go for inroom APs (hospitality wall mounted APs). We did a trial in Jan / Feb with 2 corridors of a block. It would have been better to trial a whole block but it wasn’t possible.
The trial showed much improved results. There were still some issues but when investigated these were either client issues or a software bug on the wireless AP. However, with in-room APs you need to keep the power at very low values and keep an eye on CCI. Due to the attenuation between rooms isn’t too bad. However, between floors there is a bit of bleed through.
> 3) Do you have any definitions of acceptable service to help us know when we have a good enough service, for example, is one disconnection a day acceptable (I think so, but some are as frequent as within 10 minutes, but there does not seem to be a regular pattern alas).
There are many reasons that a client can disconnect and it maybe no fault of the wireless infrastructure.
> We are using expensive CISCO access points in the corridor rather than cheap ones per room.
The requirements of the clients (HD Streaming media) and the increased number of devices requires better wireless networks. The problem is it is cheap to just put APs in corridors. I think the days of APs in corridors for new build residences are numbered. In room hospitality APs seems the way forward (or in room traditional APs).
>
> It is frustrating – the students can connect ok, but after varying periods, get disconnected.
>
> Grateful for any pointers – our network team thought a shout to the list might be useful. I’m not a network techy myself however!
>
> Best wishes,
>
> Jim
Knowing what is wrong with RF environment which is causing the clients to disconnect is probably the best starting place. e.g. is it poor SNR, high duty cycle, CCI, rubbish client driver.
Surveying may also help identify problems
Scott Armitage
The University of Lincoln, located in the heart of the city of Lincoln, has established an international reputation based on high student satisfaction, excellent graduate employment and world-class research.
The information in this e-mail and any attachments may be confidential. If you have received this email in error please notify the sender immediately and remove it from your system. Do not disclose the contents to another person or take copies.
Email is not secure and may contain viruses. The University of Lincoln makes every effort to ensure email is sent without viruses, but cannot guarantee this and recommends recipients take appropriate precautions.
The University may monitor email traffic data and content in accordance with its policies and English law. Further information can be found at: http://www.lincoln.ac.uk/legal.
|
