Anybody care to muse on Wi-SIP vs. SIP-DECT? My limited research indicates that none of the WiSip phones will ever be able to match the performance of DECT phones. Maybe I'm wrong but a Wi-SIP phone seems like a DIESEL sports car. There is nothing wrong with the technology, but it seems like a shoe-horned fit into the requirements of a wireless endpoint. DECT uses a wireless radio layer that was engineered from the ground-up with the design priorities of a wireless endpoit. I notice that the standby times of Wi-SIP vs. SIP-DECT are a great illustration of this point. I guess there's no low-power way to participate in a WiFi network, hense standby battery life that sucks in Wi-SIP. I've never actually demoed a Wi-SIP phone on premesis, but if the range of my WiFi LAPTOP vs. my DECT 6.0 headset is any indication, (DECT more than double the range) I'd guess it to be quite hard to make a case for Wi-SIP unless you're doing some straight-up network application integration right onto the phone. Can anyone speak to this? -Karl
On Friday 29 August 2008 09:58:56 Karl Fife wrote:> Anybody care to muse on Wi-SIP vs. SIP-DECT? > > My limited research indicates that none of the WiSip phones will ever be > able to match the performance of DECT phones. Maybe I'm wrong but a > Wi-SIP phone seems like a DIESEL sports car. There is nothing wrong > with the technology, but it seems like a shoe-horned fit into the > requirements of a wireless endpoint. DECT uses a wireless radio layer > that was engineered from the ground-up with the design priorities of a > wireless endpoit. > > I notice that the standby times of Wi-SIP vs. SIP-DECT are a great > illustration of this point. I guess there's no low-power way to > participate in a WiFi network, hense standby battery life that sucks in > Wi-SIP. > > I've never actually demoed a Wi-SIP phone on premesis, but if the range > of my WiFi LAPTOP vs. my DECT 6.0 headset is any indication, (DECT more > than double the range) I'd guess it to be quite hard to make a case for > Wi-SIP unless you're doing some straight-up network application > integration right onto the phone. Can anyone speak to this?I think the primary reason for going Wi-SIP is the buildout factor. Yes, while range is limited in WiSIP, the fact that the phone is entirely self-contained means that you can build out additional WAPs, transitioning between them as the phone moves around an area. Additionally, an existing wireless infrastructure can be taken advantage of, instead of building a separate network for the phones. While DECT repeaters exist that serve this same purpose, the tools to ensure that all areas within a service area are served are still a little lacking. Basically, you're left with deploying stations, running around with a phone to every nook and cranny, hoping the battery life stands up, and deploying repeaters in a haphazard fashion to address the issues. Compare that to the professional tools you can find to fully deploy Wifi hotspots on the first try, and you'll find a much less painful deployment cycle. -- Tilghman
Karl Fife wrote:> Anybody care to muse on Wi-SIP vs. SIP-DECT? > > My limited research indicates that none of the WiSip phones will ever be > able to match the performance of DECT phones. Maybe I'm wrong but a > Wi-SIP phone seems like a DIESEL sports car.Just for fun! http://www.cumminsracing.com/ Rod --> There is nothing wrong with the technology, but it seems like a > shoe-horned fit into the requirements of a wireless endpoint. DECT > uses a wireless radio layer that was engineered from the ground-up > with the design priorities of a wireless endpoit. > > I notice that the standby times of Wi-SIP vs. SIP-DECT are a great > illustration of this point. I guess there's no low-power way to > participate in a WiFi network, hense standby battery life that sucks in > Wi-SIP. > > I've never actually demoed a Wi-SIP phone on premesis, but if the range > of my WiFi LAPTOP vs. my DECT 6.0 headset is any indication, (DECT more > than double the range) I'd guess it to be quite hard to make a case for > Wi-SIP unless you're doing some straight-up network application > integration right onto the phone. Can anyone speak to this? > > -Karl > > _______________________________________________ > -- Bandwidth and Colocation Provided by http://www.api-digital.com -- > > AstriCon 2008 - September 22 - 25 Phoenix, Arizona > Register Now: http://www.astricon.net > > asterisk-users mailing list > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users
On Fri, 29 Aug 2008, Karl Fife wrote:> Anybody care to muse on Wi-SIP vs. SIP-DECT? > > My limited research indicates that none of the WiSip phones will ever be > able to match the performance of DECT phones. Maybe I'm wrong but a > Wi-SIP phone seems like a DIESEL sports car. There is nothing wrong > with the technology, but it seems like a shoe-horned fit into the > requirements of a wireless endpoint. DECT uses a wireless radio layer > that was engineered from the ground-up with the design priorities of a > wireless endpoit. > > I notice that the standby times of Wi-SIP vs. SIP-DECT are a great > illustration of this point. I guess there's no low-power way to > participate in a WiFi network, hense standby battery life that sucks in > Wi-SIP. > > I've never actually demoed a Wi-SIP phone on premesis, but if the range > of my WiFi LAPTOP vs. my DECT 6.0 headset is any indication, (DECT more > than double the range) I'd guess it to be quite hard to make a case for > Wi-SIP unless you're doing some straight-up network application > integration right onto the phone. Can anyone speak to this?I've used both - with good results. However, I've also done a *lot* of network building using Wi-Fi and it's not that good for telephony. Firstly it's half duplex (so's DECT, GSM, etc. but that's OK, as it's designed that way), and what I've found, certinly in the consumer and some of the access point aimed at businesses is that the radio turn-around time sometimes becomes significant. In tests, I found that most units would degrade horribly when the packet size was < 140 bytes or so. VoIP packets are 160 bytes, so we're mostly OK there. The packet size and frequency (50 packets a second, both ways) is the biggest killer for access points. They're really optimised for streaming data one way, so big 1500 byte packet down, tiny ACK packet back. Intersperse that with VoIP and you get issues. Even with fancy access point that have traffic management, sending just one big 1500 byte packet can have an impact on a stream on 160 byte packets that need to be sent at a specific rate. So you'll get away with it on your home network (or small office) if you're the only one using Wi-Fi. I make calls with my Nokia E90 + SIP & Wi-Fi and for the most part, it's fine. But get someone else on the same access point and have them do some file-bashing to a local server and you'll get issues. If you can go to the expense of running a totally separate Wi-Fi network just for VoIP then you'll probably be fine, but my old AP barely copes with 2 concurrent calls. 3 calls and you start to get loss. Then you've got the issues of channel separation. There are only 3 true clear channels in the spectrum that don't overlap. I can see 5 other access points from my office now (and the town CCTV system runs in the 2.4GHz band too )-: and I'm in a rural location, so what hope is there in a busy office complex... So Wi-Fi works, but only just... DECT with repeaters seems so much better... Gordon
On 29/08/2008 Karl Fife wrote:> Anybody care to muse on Wi-SIP vs. SIP-DECT?DECT is an optimised wireless voice system, Wi-Fi isn't. Works for me :) But seriously, I have DECT phones with battery life of a week, I don't think any Wi-Fi device will come within a mile of that (witness the poor life of Nokia Wi-Fi equipped phone batteries). >Maybe I'm wrong but a Wi-SIP phone seems like a DIESEL sports car. http://www.americanlemans.com/News/Article.aspx?ID=1872 Phil
On Fri, 29 Aug 2008 09:58:56 -0500, Karl Fife wrote:>Anybody care to muse on Wi-SIP vs. SIP-DECT? > >My limited research indicates that none of the WiSip phones will ever be >able to match the performance of DECT phones. Maybe I'm wrong but a >Wi-SIP phone seems like a DIESEL sports car. There is nothing wrong >with the technology, but it seems like a shoe-horned fit into the >requirements of a wireless endpoint. DECT uses a wireless radio layer >that was engineered from the ground-up with the design priorities of a >wireless endpoit. > >I notice that the standby times of Wi-SIP vs. SIP-DECT are a great >illustration of this point. I guess there's no low-power way to >participate in a WiFi network, hense standby battery life that sucks in >Wi-SIP. > >I've never actually demoed a Wi-SIP phone on premesis, but if the range >of my WiFi LAPTOP vs. my DECT 6.0 headset is any indication, (DECT more >than double the range) I'd guess it to be quite hard to make a case for >Wi-SIP unless you're doing some straight-up network application >integration right onto the phone. Can anyone speak to this?I've used both fairly extensively in a home office setting. DECT is the clear winner. That said, the current crop of wifi APs and SIP handsets can do a good job, but it's gonna be more work and maybe a little more expensive that you think. You need newer APs with WMM. Unless there's a truly compelling reason to go with converged voice+data over wifi I'd recommend DECT in most cases. Michael -- Michael Graves mgraves<at>mstvp.com http://blog.mgraves.org o713-861-4005 c713-201-1262 sip:mjgraves at pixelpower.onsip.com skype mjgraves fwd 54245