At 6/20/2010 12:32 AM, Faisal Imtiaz wrote: >You know your stuff in-side out, hands down there is no argument about >that :)
Thanks. :-) >Getting back to your original quest... You are going to find the following:- > >The non-licensed wireless world is not as mature as the wire line >world... think of today's wire less world being what the wire line world >used to be about 10 -15 years back. Most of what you are citing from the >Ethernet World, only became available and in common use in the last 10 >years or so... before that, everyone was happy doing conversions from >TDM ...(speaking loosely). > >In the wireless world of today, especially what folks here deal with, >have some set outer boundaries ... a few of these are things like... >performance, based on standard(s) , LOW COST, small in power >consumption, etc etc... It is different... in particular, the WISP community knocks a few zeroes off of the allowable costs. I like that... you can put up a node for what your basic Bell would pay for a jumper cable or the like. This is the only way to make service affordable in small clusters, like <50/node. The FCC-blessed approach, in contrast, is to have a rural ILEC spend $20k+ per subscriber to pull glass or hybrid fiber-copper to the neighborhood, and charge the rest of the country for it via the USF. In this case we're in the outskirts of an ATT exchange, so there's no USF for them, and thus no service beyond dial tone. In the wireline world, we look at Vyatta as this super-low-cost alternative to that company that rhymes with Crisco. Here, Vyatta is that high-end alternative to a Latvian import. Those other guys, the ones that basically control the IETF, don't play. I like that too... >... >BTW, Aaron Kaplan was trying to say, in not too many words.. that most >of the "mesh" networks which have utilized the traditional Wireline >protocols, (weather they are single frequency or not) have the usual >problem .(most wireline protocols are not concerned with link >quality...), and this is the reason why they developed the OSLR ... >which takes link quality into account as well when making routing >decision.. but you are not going to find OSLR in commercial radios.... >not at the moment... That's one reason why MicroTik's HWMPplus looked attractive. It is designed for wireless, and claims to take link conditions into account. It looks like a direct competitor for OSLR. >If you look at all of the folks who are delivering successful mesh >products, you will find them to be using 'proprietary' developed >mechanisms to deal with the issues..e.g. Ruckus Wireless uses it's >special antennas and a 'zone controller' to keep the Mesh radios in tip >top shape, by dynamically adjusting all of the parameters on a real >time basis.. > >As far as finding a multi-radio board... there are a few available best >to see the link to Wili Box site that I had sent in an earlier email... >they list out a number of mfg. for both the sbc's and the radios.. the >question you will have to figure out is..on what part of the 'network >design' ... 'ip routing ?' you will be willing to make a compromise >on...and you still have not addressed the question of >"Antennas"....:).... after using a good working 802.11n radios with >MiMo Antennas... it is rather hard to go back to regular stuff... I'm definitely interested in MIMO. LTE, which is starting to be rolled out in the CMRS world and, separately, in the public safety radio world, includes MIMO, both beamforming for range and parallel transmission for close-in speed. If I could find a pole-top system (mesh node) that did dynamic MIMO instead of using sectorized antennas, it'd be a serious win. Also, 4x4 MIMO is probably coming out soon, and at 5.8 GHz a proper 4x4 antenna is still pretty small, and has of course a lot more gain (and interference notching) than 2x2. WiMAX can have MIMO too (it's an option), but I haven't seen it in the unlicensed low-cost world. >Faisal Imtiaz >Snappy Internet& Telecom > > > >On 6/19/2010 8:50 PM, Fred Goldstein wrote: > > > > This is one of the problems with any kind of "best efforts" routing > > or bridging. Loss does accumulate. Of course it's the > > single-frequency meshes where loss goes totally gaga. One of the > > advantages of Carrier Ethernet with Q-in-Q is that CIRs can be > > assigned to different points along the way, with reserved capacity, > > so the near-in nodes don't hog everything. I don't think HWMPplus > > does full CE, but it may have some tools to play with. If anybody > > can suggest a better software load for a field-mountable multi-radio > > processor, notably one that does MEF CE, I'm not wedded to > > MicroTik. This is interim, after all; we hope to have our own code > > at some point. > > > > On the Layer 2 v 3 thing, the distinction is artificial. Off the > > shelf, LAN-oriented L2 switching does dumb bridging, based on an > > assumption that it's all on-site with plenty of zero-cost orange hose > > bandwidth to play with. So STP just avoids loops. IP itself is > > really a layer 2 protocol too! This is non-obvious, but an IP > > address names the interface, not the application or host, and thus it > > is also a layer 2 address. TCP/IP doesn't even have a network layer, > > just this stub that assigns two-to-three-level second names (IP > > addresses to interfaces whose MAC address is totally flat. If you > > assign node IDs in Layer 2, it becomes smarter than IP, and IP can > > thus be run as a dumb stub protocol. > > > > (Suggested reading: Patterns in Network Architecture: A Return to > > Fundamentals, by John Day.) -- Fred Goldstein k1io fgoldstein "at" ionary.com ionary Consulting http://www.ionary.com/ +1 617 795 2701 -------------------------------------------------------------------------------- WISPA Wants You! Join today! http://signup.wispa.org/ -------------------------------------------------------------------------------- WISPA Wireless List: [email protected] Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
