Essentially WiFi over 900 MHz, can anyone comment on the likelihood that this emerging standard will fly, i.e., that we will begin seeing chipsets and adoption sometime in the next year or two? http://en.wikipedia.org/wiki/IEEE_802.11ah -- Randy Yates Digital Signal Labs http://www.digitalsignallabs.com
802.11ah
Started by ●February 21, 2014
Reply by ●February 21, 20142014-02-21
On Fri, 21 Feb 2014 11:07:22 -0500, Randy Yates <yates@digitalsignallabs.com> wrote:>Essentially WiFi over 900 MHz, can anyone comment on the likelihood that >this emerging standard will fly, i.e., that we will begin seeing >chipsets and adoption sometime in the next year or two? > >http://en.wikipedia.org/wiki/IEEE_802.11ah >-- >Randy Yates >Digital Signal Labs >http://www.digitalsignallabs.comFor what application? I can think of a few things that it might be used for, and a few things for which it might not be well-suited. I doubt that you'll see laptops/tablets/handsets with it, for example. Eric Jacobsen Anchor Hill Communications http://www.anchorhill.com
Reply by ●February 21, 20142014-02-21
eric.jacobsen@ieee.org (Eric Jacobsen) writes:> On Fri, 21 Feb 2014 11:07:22 -0500, Randy Yates > <yates@digitalsignallabs.com> wrote: > >>Essentially WiFi over 900 MHz, can anyone comment on the likelihood that >>this emerging standard will fly, i.e., that we will begin seeing >>chipsets and adoption sometime in the next year or two? >> >>http://en.wikipedia.org/wiki/IEEE_802.11ah >>-- >>Randy Yates >>Digital Signal Labs >>http://www.digitalsignallabs.com > > For what application? I can think of a few things that it might be > used for, and a few things for which it might not be well-suited. I > doubt that you'll see laptops/tablets/handsets with it, for example.I agree - I wouldn't expect laptops/tablets/handset to have it. The application is pretty clearly embedded devices such as M2M, industrial automation, etc., e.g., due to provisions for power savings and low bitrate modes being built in. I think the idea is to bring WiFi to challenging RF environments such as metal buildings, long distances, more multipath (e.g., from foliage). -- Randy Yates Digital Signal Labs http://www.digitalsignallabs.com
Reply by ●February 21, 20142014-02-21
On Friday, February 21, 2014 2:24:04 PM UTC-5, Randy Yates wrote:> eric.jacobsen@ieee.org (Eric Jacobsen) writes: > > > > > On Fri, 21 Feb 2014 11:07:22 -0500, Randy Yates > > > <yates@digitalsignallabs.com> wrote: > > > > > >>Essentially WiFi over 900 MHz, can anyone comment on the likelihood that > > >>this emerging standard will fly, i.e., that we will begin seeing > > >>chipsets and adoption sometime in the next year or two? > > >> > > >>http://en.wikipedia.org/wiki/IEEE_802.11ah > > >>-- > > >>Randy Yates > > >>Digital Signal Labs > > >>http://www.digitalsignallabs.com > > > > > > For what application? I can think of a few things that it might be > > > used for, and a few things for which it might not be well-suited. I > > > doubt that you'll see laptops/tablets/handsets with it, for example. > > > > I agree - I wouldn't expect laptops/tablets/handset to have it. > > > > The application is pretty clearly embedded devices such as M2M, > > industrial automation, etc., e.g., due to provisions for power savings > > and low bitrate modes being built in. > > > > I think the idea is to bring WiFi to challenging RF environments such as > > metal buildings, long distances, more multipath (e.g., from foliage). > > -- > > Randy Yates > > Digital Signal Labs > > http://www.digitalsignallabs.comSeems like if it will really "cover 1 km" (from the wiki article), this gives a radius of just over 1/2 km. Does this band have to be licensed? That in itself seems like an impediment to general acceptance. Clay
Reply by ●February 21, 20142014-02-21
On Fri, 21 Feb 2014 12:06:50 -0800 (PST), clay@claysturner.com wrote:>On Friday, February 21, 2014 2:24:04 PM UTC-5, Randy Yates wrote: >> eric.jacobsen@ieee.org (Eric Jacobsen) writes: >> >> >> >> > On Fri, 21 Feb 2014 11:07:22 -0500, Randy Yates >> >> > <yates@digitalsignallabs.com> wrote: >> >> > >> >> >>Essentially WiFi over 900 MHz, can anyone comment on the likelihood that >> >> >>this emerging standard will fly, i.e., that we will begin seeing >> >> >>chipsets and adoption sometime in the next year or two? >> >> >> >> >> >>http://en.wikipedia.org/wiki/IEEE_802.11ah >> >> >>-- >> >> >>Randy Yates >> >> >>Digital Signal Labs >> >> >>http://www.digitalsignallabs.com >> >> > >> >> > For what application? I can think of a few things that it might be >> >> > used for, and a few things for which it might not be well-suited. I >> >> > doubt that you'll see laptops/tablets/handsets with it, for example. >> >> >> >> I agree - I wouldn't expect laptops/tablets/handset to have it. >> >> >> >> The application is pretty clearly embedded devices such as M2M, >> >> industrial automation, etc., e.g., due to provisions for power savings >> >> and low bitrate modes being built in. >> >> >> >> I think the idea is to bring WiFi to challenging RF environments such as >> >> metal buildings, long distances, more multipath (e.g., from foliage). >> >> -- >> >> Randy Yates >> >> Digital Signal Labs >> >> http://www.digitalsignallabs.com > > >Seems like if it will really "cover 1 km" (from the wiki article), this gives a radius of just over 1/2 km. Does this band have to be licensed? That in itself seems like an impediment to general acceptance. > >ClayThere's an ISM band at 900MHz, which I think is the target. There are 900MHz unlicensed bands in many global markets, hence the standardization. The adjustment for "more multipath" would be formally increasing the length of the guard interval for longer range. Foliage or not, metal buildings or not, shouldn't matter. 802.11a/g/n is already used in those environments with the larger subcarrier sets, etc. It looks like many of the optimizations were for low power consumption. Eric Jacobsen Anchor Hill Communications http://www.anchorhill.com
Reply by ●February 22, 20142014-02-22
The longer wavelength (over 2G ISM) helps. Shadowing is less of a problem, also the path loss coefficient is AFAIK better for longer distances. If anybody is interested, comprehensive radio path models can be found in in "WINNER" project deliverables which are freely available on the web. _____________________________ Posted through www.DSPRelated.com
Reply by ●February 22, 20142014-02-22
On Sat, 22 Feb 2014 09:38:48 -0600, "mnentwig" <24789@dsprelated> wrote:>The longer wavelength (over 2G ISM) helps. Shadowing is less of a problem, >also the path loss coefficient is AFAIK better for longer distances.The longer wavelength helps because the resonant antenna is larger and collects more energy. That's the basic mechanism behind path loss being more favorable at lower frequencies. Materials penetration changes a bit, too, which also generally helps.>If anybody is interested, comprehensive radio path models can be found in >in "WINNER" project deliverables which are freely available on the web.Interesting. Thanks.>_____________________________ >Posted through www.DSPRelated.comEric Jacobsen Anchor Hill Communications http://www.anchorhill.com
Reply by ●February 23, 20142014-02-23
I think there's more to it. Generally, longer wavelength acts less like a light beam, bends easier around obstacles and the like. It shows quite clearly in RC flying: Generally, modern GHz radios is extremely robust as long as there is line-of-sight. But, clowning around with obstacles or the terrain is a bad idea, where an old-fashioned FM radio would work just fine. I think the FPV folks prefer it for that reason (and less interference with video downlink) _____________________________ Posted through www.DSPRelated.com
Reply by ●February 23, 20142014-02-23
On Sun, 23 Feb 2014 04:30:11 -0600, "mnentwig" <24789@dsprelated> wrote:>I think there's more to it. Generally, longer wavelength acts less like a >light beam, bends easier around obstacles and the like.Knife-edge diffraction does have some frequency dependence, but it's not usually a driving factor in frequency selection. Materials penetration does come into play, though, and getting through trees, walls, etc., is generally better at lower frequencies.>It shows quite clearly in RC flying: Generally, modern GHz radios is >extremely robust as long as there is line-of-sight. But, clowning around >with obstacles or the terrain is a bad idea, where an old-fashioned FM >radio would work just fine. I think the FPV folks prefer it for that reason >(and less interference with video downlink)Multipath sensitivity may come into play, too, I don't know, and often the maximum transmit power is different in different bands. Usually applications like that just go to the band with regulations that allow the most power, but, again, lower frequencies use larger dipole antennas with more affective area and therefore more gain. The best power/gain combination will fundamentally provide the best range and expected performance. Eric Jacobsen Anchor Hill Communications http://www.anchorhill.com
Reply by ●February 24, 20142014-02-24
Eric Jacobsen <eric.jacobsen@ieee.org> wrote:> On Fri, 21 Feb 2014 11:07:22 -0500, Randy Yates > <yates@digitalsignallabs.com> wrote:>> Essentially WiFi over 900 MHz, can anyone comment on the >> likelihood that this emerging standard will fly, i.e., that >> we will begin seeing chipsets and adoption sometime in the >> next year or two?>>http://en.wikipedia.org/wiki/IEEE_802.11ah(snip)> For what application? I can think of a few things that it might be > used for, and a few things for which it might not be well-suited. I > doubt that you'll see laptops/tablets/handsets with it, for example.In all the ones I see, frequencies are increasing, not decreasing. As higher frequency devices get cheaper, that is the direction to move into. Lower noise, for one. (Stay away from microwave ovens, though.) Also, higher frequencies mean smaller antennas, which everyone likes. I thought 900MHz was about where cellphones were (maybe aren't anymore) which would make things harder. -- glen
