I sympathize completely - with all my customers wanting 802.11b out in the middle of nowhere 8-12 miles from my base station (AP) and wanting cordless phones, the senao (engenius) sn900/920 series has become the favorite. It's not cheap - approaching the price of an access point (and a good one at that) but the base and handset have a few neat features. I must caution that I have one customer who has had nothing but bad luck with his Senao - we plan to take it and put it on my bench and find out what's going on. His experience does not follow mine.
As for the Senao/Engenius cordless phones #1 - TRUE spread spectrum (most digital spread spectrum are only digital signaling meaning the button pushes are digitally modulated from the handset to the base) - spread spectrum in the sense that they are 150 khz or wider bandwidth analog modulation. The engenius/senao phones use the lucent chipset (and to my knowledge are the only ones using lucent's chipset) - they use the entire band from 902-928 and only send data. It's the spread spectrum in the military sense - don't waste your time tracking or decyphering it. You won't succeed. I've got $50 for the first person who can decode the audio from my Senao / Engenius using a 902-928 mhz scanner and all the computing power they can muscle. I'll even help them do it. #2 - they are built like a tank. Cast aluminum chassis. Alphanumeric display with callerid. Backlit everything. Adjustable everything. Multiple base and handset registry. #3 - variable power - from miliwatts up to 1000 mw (1 WATT) - most 2.4 G phones are 1-5 miliwatts - maybe 20 at the most. They have no power amp stage in them. 1 Watt goes a long way in 900 mhz, esp with an outdoor antenna. The senao base (stock, unmodified) will diflect a bird wattmeter with a 1000 mhz 5W slug in it to 1W. **NO** other FCC US sellable cordless can do that. #4 - cellular style dial then send dialing. Memory with name/number. Caller ID with name/number, and send to redial. #5 - handset to handset FULL DUPLEX 1WATT DIGITAL SPREAD SPECTRUM walkie talkies (if you have more than 1 handset, you can "call" from one to another without using the base - take the handsets to disneyland and use them as radios No FRS listeners in your conversation - and better range! Take the money you were going to use to buy a pair of FRS radios and buy a 2nd senao handset instead - full duplex means no push to talk - just like a phone! #6 - up to 4 lines / 16 handsets - select which line you dial out on and how each handset handles incomming calls for each handset. (this differs slightly on their 4-line model vs. buying 4 ea of their 1 line models) #7 - ability to transfer calls from one handset to another, and ability to put a call on hold, swap batteries, and take it off hold and keep talking. (charger holds a spare battery on charge for you for this purpose.) - at 1 Watt, the battery life isn't great, but that's the price you pay for a good headache these days :) The senao / Engenius is more like having your own small cellsite than a cordless phone. No buzzing - no glitches, and multiple talk paths so you can have 2 or more bases and 2 or more handsets in use simultaneously, plus another handset to handset call without even using a base. The audio is absolutely perfect. People do not know you are on a cordless even in 2 hour long calls. Above all - SECURITY - nobody will be listening to your conversation -- except for the seimens, most 2.4 "digital spread spectrums" are really just wideband analog and can be heard on any good scanner that goes to 2.4G (very few do) and has a wideband audio setting. Many 2.4 G listeners don't even use fancy scaners - just 2.4 G downconverters ($30) and common everyday scanners to tune to 200 Mhz. I've won more bets by people who think their 2.4G "spread spectrum secure cordless" is good enough to talk about banking info than I can keep track of (at least $50!) My senao's are old - 3 yrs + - and they all still work. I think the average cordless dies in a year. Their construction is very impressive. I've taken them apart on the bench, upped the power output, adjusted the frequency stability of their master clock, and I'm very impressed with the castings and construction. Those 2 mods turn a great phone into an exceptional phone. Everett > > Everett > > Thanks for the great analysis. fundamental problem is that most of the > 900MHz phones are disappering from the market. You go to local Store you > find couple of models and thats is it!!!!! It seems Cordless phone > manufacturers created wave that 2.4GHz phones are better, better range and > good voice quality and all B... S... > > I had to buy one online and that also crapy from panasonic..... > > lalit > > ----- Original Message ----- > From: <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Cc: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; > <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> > Sent: Friday, October 10, 2003 6:14 PM > Subject: Re: [BAWUG] What 2-line 2.4Ghz phones coexist with 802.11B? Will > freq. hopping kill my network? > > > > My suggestion - which is worth just what you paid for it - is keep your > > 802.11 area clean of other 2.4G transmitters. Clean the door seal on the > > microwave oven. Buy 900 Mhz phones (I have 4 Senao's and LOVE them! - > > external antennas and I can walk the dog 8 blocks any direction and take/ > > make calls) - avoid anything 2.4 G - even if it claims to work with > 802.11x > > > > The simple reason is that having another transmitter nearby a very > sensitive > > receiver is that even if they are NOT on the same frequency, the nearby > > xmitter will overpower the sensitive receiver's front end resulting in > > what is known as "de-sense" or decreasing the sensitivity of the receiver > > due to a nearby strong signal from the transmitter (phone, video rabbits > > [rent-a-cop companies like these for spying on suspect employees inside > > major corporations because they are too lazy to run 75 ohm coax - I > watched > > IT and security duke it out at one major silicon valley firm - the one > that > > started it all - when we found a hidden camera with a spectrum analyzer > > causing problems for their 802.11b system. Ever find a sprinkler head > with > > a 2.4 G antenna? It's not there for fire protection.) > > > > Yep - they're not on the same channel - but the degredation (sic?) is > still > > there to the point that you'd be better off with just a single 802.11x > > network and nothing else. You might never see it. Or you might have dead > > spots that otherwise wouldn't be there. > > > > Even multiple 802.11x deployments (big buildings for example) need to take > > into account desense problems. Sectorized antennas and natural > attenuators > > like metal walls help in the engineering of these systems. Just tossing a > > bunch of cheap APs from fry's into an empty building often results in a > bad > > reputation for 802.11x - people complain bitterly about problems from too > > many APs improperly installed as too few. One guy I met bought 11 APs > from > > frys with their budget for wireless - put them (you guessed it) on > channels > > 1 through 11 - and tossed them above the dropped ceiling - every 4th tile > > had an access point. Same SSID on all. Laptops wouldn't stay assoc'ed > for > > more than a few seconds - pages stopped loading mid-page - a real "CF". > One > > well designed AP and antenna system would have done the job better. > > > > Protect your 2.4G band from un-needed stuff and you'll get great > performance > > from your 802.11 hardware. Use 900 and 5.8 G if you run 802.11b/g - or if > > you've got spy cameras that were there first, buy 802.11a! > > > > Everett > > -- > general wireless list, a bawug thing <http://www.bawug.org/> > [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless -- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless
