First, we would need a full definition of "seamless"...
Richard wrote: > Is there really such a thing as WiFi operating "seamlessly"? I assume > that would be like the operation of cellular service. Wireless computer > interface to the Internet can be accomplished by "dial up" through the > PSTN Cellular and that would be seamless, but other than that kind of > service, if you move from one WiFi hot spot to another, the OS has to > re-acquire connection via the new hot spot. > > I have two WAP's and would like to configure so that it would be > seamless to move between them, anyone know how? > > > Richard, NCT > N6GPP > > On 3/2/06, Jack Unger <[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>> wrote: > > > Roaming between access points may result in applications stopping > termporarily or dropping permanently. > > > Sankaran Somasundaram wrote: > > I have some basic question again. what are the problems that > would arise > > with "seamless wi-fi"..One problem i know is interference because > of the > > unregulated unlicensed region wi-fi operating in. what else could > be the > > problems when a seamless wi-fi is promised? > > > > your help is appreciated. > > > > Thanks, > > Sankar > > > > > > > > On 2/28/06, Sankaran Somasundaram <[EMAIL PROTECTED] > <mailto:[EMAIL PROTECTED]> > > <mailto: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>>> wrote: > > > > Thanks a lot Kevin and Mr.Thompson. > > > > > > On 2/27/06, Jim Thompson <[EMAIL PROTECTED] > <mailto:[EMAIL PROTECTED]> <mailto:[EMAIL PROTECTED] > <mailto:[EMAIL PROTECTED]>>> > > wrote: > > > > > > kevincw01 wrote: > > > >>I don't beleive it's this simple. One problem is that the range for > >> 802.11g is actually less than 802.11b at the maximum throughput. > >> > > The primary reason for this is that at the maximum > modulation speed > > (54Mbps .vs 11Mbps) a much higher Eb/No (SNR) is required > for > > 11g than > > for 11b. > > > > At (nearly) equivalent bit rates (12Mbps 11g .vs 11Mbps > 11b) the > > Eb/No > > curves are almost identical. > > > > If your environment has a high delay spread (lots of > multipath), > > then > > 11g's 800ns guard interval may get a signal through a lot > > "farther" than > > 11b's nominal 110ns tollerance for delay spread. > > > >>So you have to decide, do you want the range for the max > > throughput or at > >>just the point before it stops working? Another problem is that the > >>power drain is largely dependent on the manufactuer's strength > > of the > >>radio. All radios are not the same strength. Off the top of my > > head, > >>I think many pcmcia 802.11b cards are 150mW but definiteily not all > >>(don't quote me on that, it's just a number floating around in > > my head > >>that seems right). So you'd probably have to take the average > > here, or > >>maybe different numbers for different strengths... Then > > ofcourse the > >>cost is going to be all over the map, good luck on that one. > >> > >> > > The original questions are unaswerable without a lot more > > information. > > > > However, the Eb/No (SNR) curves for the WiMax PHYs, > operated in > > unlicensed spectrum, at equivalent bit rates are > approximately > > the same, > > and anyone operating WiMax or WiFi in unlicensed spectrum > must > > operate > > under 47 CFR Part 15.247 (ISM) or 15.407 (U-NII), so > there is *no* > > inherent advantage of either WiMax or WiFi (compared to > each other) > > under these conditions. > > > > If you don't believe me, I invite you to study the IEEE > > documents carefully. > > > > *most* 802.11b cards operated with 16-17dBm (32mW - 50mW) of > > transmit > > power. There are specialty cards with 100mW or more of > transmit > > power > > available. All other things being equal, building a > high-power > > 11g card > > is more expensive than building a high-power 11b card, due to > > peak-to-average power ratio issues. Since WiMax also uses > > OFDM, with > > similar modulation envelopes, it will also face PAPR .vs > linearity > > > > > > > > > > > > -- > Jack Unger ([EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>) - > President, Ask-Wi.Com, Inc. > Serving the License-Free Wireless Industry Since 1993 > Author of the WISP Handbook - "Deploying License-Free Wireless WANs" > -- > "Being a bit scattered tends to be a trait of highly imaginative > people." > The more you rattle the marbles around in your brain, the more > creative new connections you make, as it were > – connections that might be lost on those focusing intently on just > the red ones. > - Ed Vogel, University of Oregon, Department of Neuroscience > -- Jack Unger ([EMAIL PROTECTED]) - President, Ask-Wi.Com, Inc. Serving the License-Free Wireless Industry Since 1993 Author of the WISP Handbook - "Deploying License-Free Wireless WANs" True Vendor-Neutral WISP Consulting-Training-Troubleshooting Phone (VoIP Over Broadband Wireless) 818-227-4220 www.ask-wi.com --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "SOCALWUG" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/SOCALWUG SOCALWUG website: http://www.socalwug.org -~----------~----~----~----~------~----~------~--~---
