Re: [WISPA] Basic Mesh Theory
No im not falling for that trap. Your example used a 100% node to node connection rate, that is not reasonable for wireless. 2 to 5 radios/node is. This reduces the network update messages. My idea with a 3 radios is 1 BH AP, 1 BH CPE, 1 Client AP. The BH CPE should be smart enough to know where nodes are physically and be able to have the BH CPE jump from one of the 3 to 5 nodes it can see(this is optimal in my opinion). Cell sizes should be small with short high capacity bh's. This is just a temp solution till the wisp can string copper to connect the APs. Pure wisps simply will not survive with out wired infrastructure beyond the upstream. To this end mesh like Lonnie has included is a good step when used correctly. Locust World mesh is ahead of the meshing game but there Wianna totally detracts from it. Jeromie Matt Liotta wrote: My example used wireless P2P links, which has no inherent weakness over fiber P2P links from a topology point-of-view. It would appear you are falling into the same trap as others by forcing mesh to be something it is not. Mesh is just a network topology; no more, no less. Sure it is possible to come up with specific examples of wireless-based mesh networks being terrible ideas, but that doesn't mean there is anything wrong with mesh itself. I would argue that in almost all cases the topology is not what is at fault. -Matt Jeromie Reeves wrote: There is a very big difference from fiber mesh and wireless mesh. Wireless is classicly a bunch of HDX links where fiber is PtP links. Your example doesnt make it clear that the difference is what cause's 802.11[a|b|g] mesh suck and fiber/copper mesh's not suck. The solution is multi radio units that can select peers based on more then just essid (channel, hop count to the edge, packet loss, ect) Jeromie Matt Liotta wrote: Attached is a quick rundown of basic mesh theory that I put together in light of the recent thread. It hasn't been peer reviewed or edited, which I would normally do before sharing publicly. But since I only wrote because of a thread on this list I figured I would just share it. Feel free to pick it apart. I do want to point out a couple of things though. First, this was written in a generic way only covering mesh as a theory. As written it can be applied to various transport technologies from fiber to wireless; though I do provide an example using wireless P2P links. Applying mesh theory to wireless P2MP or ad-hoc networks would require special coverage. -Matt -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Basic Mesh Theory
Jack Unger wrote: You raise some good points... and here are some more differences between Matt's fully-meshed WIRED network example and the real-world conditions under which WIRELESS mesh networks are so often deployed today. My example actually used wireless P2P links, although it was meant to apply just as well to other mediums. 1) REROUTING - Only a node failure or a high peak traffic load would normally force a routing path change on a fiber/copper network. On a wireless mesh, routing path changes will also result from interference caused by other same-network nodes, interference from other networks, and interference from other wireless non-network sources. Routing path changes will also be caused by the movement of obstructions and other rf-reflective objects such as trees and vehicles. Rerouting occurs regularly with a mesh wired network due to load balancing and QoS concerns. Although, I would agree with you that in a more traditional ring topology, rerouting would only occur on a node failure or overload with a wired network. I would also like to point out that someone of the issues you raise generally only occur on street-level networks. Using a wireless mesh network on rooftops or towers avoids many of the issues you raised. At the same time, many mesh vendors now use layer2 metrics such as rssi, signal to noise ratio, and RF frame errors in addition to layer3 metrics to select the best path. I believe these layer2 metrics are required for a proper street-level network. 2. CAPACITY - Fiber/copper networks typically start out with high-capacity (compared to wireless) full-duplex links. Wireless mesh networks start out with low-capacity half-duplex links. What capacity any network starts with is up to folks deploying it and is not a function of medium. 3. CONNECTIVITY - Fiber/copper mesh network nodes have two or more paths to other nodes. Real-world wireless mesh networks may contain nodes that, in some cases (the traditional mesh definition not withstanding) only have a path to one other node. For example, obstructions may block paths to all but one (or even no) other nodes. I believe almost any real-world network is going to have paths that aren't protected. For example, we have a building that served by a single fiber path because it is not economically to have diversity at that particular building. Every other building we have on fiber is connected via diverse paths. 4. ENGINEERING - Fiber/copper mesh networks are typically properly engineered for traffic-carrying capacity, QoS, latency, etc. Real-world wireless mesh networks are typically deployed in near-total ignorance of the Layer 1 (wireless layer) conditions. That's the great attraction (IMHO) of muni-mesh networking today. These networks are thrown up in the belief that they don't need any Layer 1 design or engineering expertise and that this will allow for quick, widespread deployment. Last time I looked however, there was still no free lunch. I predict that the muni mesh networks that are thrown up today (Philadelphia will be a prime example, unless it's re-engineered correctly) will fail and fail miserably to meet the high expectations that have been raised like free or low-cost broadband for all. In addition, muni mesh networks today typically lack adequate traffic engineering and performance testing under load. I believe you are entirely correct. However, that doesn't mean that a WISP can't properly engineer a mesh network. I would suggest the above is no different than folks stringing a bunch of Ethernet hubs together and expecting their LAN to work correctly. I'm not saying that wireless mesh networks should never be used. There are certain (obstructed, short-link, low capacity) environments where they will be the best, most economical solution. I'm just saying that the false claims and marketing hype surrounding MOST (and let me repeat, MOST) of today's mesh networking claims, particularly mesh network nodes that contain just a single 2.4 GHz radio are going to come back to bite both the vendors and the cities that deploy these networks without sufficient wireless knowledge in the false belief that wireless mesh networks are just plug-and-play. Interestingly, Tropos the current poster child of wireless mesh networks is a single radio product, but all of their large networks have nodes backhauled by fixed wireless. In a sense, this means those networks are not based on a single radio. In fact, some market argue that using Canopy for backhauling Tropos --as is the case of Philadelphia-- is a better solution than to use an 802.11-based radio for backhaul like the multi-radio mesh network vendors do. -Matt -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
RE: [WISPA] Basic Mesh Theory
Jack, Let me jump in with some more thoughts on wireless mesh: I agree with you that RF engineering and RF limitations are not being fully considered in most mesh deployments. Most mesh designs I have seen are theory based and assume the full use of the unlicensed spectrum at hand. This will never be the case and therefore limits the overall capacity. I saw an RFP from the city of Miami Beach and they had done a pre-survey of the city and found the noise floor at 2.4 GHz at -70 db in most areas. Now how is one going to deploy a mesh network with the ability to overcome that? Typical answer is build more nodes closer to each other so these PDAs and laptops get enough signal. This ignores the fact that all of these close spaced nodes then create more noise for each other because they are mounted at a height where they hear each other. In high density nodes even having 2 hops will bring these networks to their knees. There is not enough spectrum to make it work and be able to load the network up. An 802.11b based system can not deal with the hidden node problem effectively enough. Even if you do have all the internode traffic on other frequencies at the high density placement required in most cities, the spectrum limits are still a big issue to have the channels to link all the nodes. I would still like to hear of a mesh network from any manufacturer that has been deployed and has a high density of users that are the kids of today. I want to see what bit torrent, VOIP and audio streaming do to a mesh in multiple hops. While we can make the argument that those services can be limited, that is only a band-aid approach as today's society is going to expect to be able to use these services in one form or another, it may take a while but it will be necessary. The cellular companies are already creating the expectation for this kids to be able to audio stream on demand. If someone has knowledge of a loaded mesh network please let me know. Don't get me wrong, I love the idea of mesh and wish it could work and want to see it work. It's just that I've been in ham radio since 1989 and was in to the packet radio technology, we as hams built networks where we dealt with all of these issues (I know it was only 1200 baud but the problems remain). There are two major problems in mesh from my viewpoint. One, if you have a carrier sense based collision avoidance system, you always have limited capacity because only one radio can talk at a time (part of the HDX problem). Two, if you do not have a carrier sense based system then you can overcome noise with a stronger signal. This causes cell site shrinkage or breathing and changes the coverage area. Most people deal with this by building transmitters closer to each other, problem is that there is limited unlicensed spectrum which is not enough room for most systems to deal with this. I really would like to see mesh work and hope to be proven wrong. There is a lot of promise in mesh implementations out there but until I have seen them under residential internet use loads I remain skeptical. Thank You, Brian Webster www.wirelessmapping.com http://www.wirelessmapping.com -Original Message- From: Jack Unger [mailto:[EMAIL PROTECTED] Sent: Monday, February 27, 2006 1:46 AM To: WISPA General List Subject: Re: [WISPA] Basic Mesh Theory Jeromie, You raise some good points... and here are some more differences between Matt's fully-meshed WIRED network example and the real-world conditions under which WIRELESS mesh networks are so often deployed today. 1) REROUTING - Only a node failure or a high peak traffic load would normally force a routing path change on a fiber/copper network. On a wireless mesh, routing path changes will also result from interference caused by other same-network nodes, interference from other networks, and interference from other wireless non-network sources. Routing path changes will also be caused by the movement of obstructions and other rf-reflective objects such as trees and vehicles. 2. CAPACITY - Fiber/copper networks typically start out with high-capacity (compared to wireless) full-duplex links. Wireless mesh networks start out with low-capacity half-duplex links. 3. CONNECTIVITY - Fiber/copper mesh network nodes have two or more paths to other nodes. Real-world wireless mesh networks may contain nodes that, in some cases (the traditional mesh definition not withstanding) only have a path to one other node. For example, obstructions may block paths to all but one (or even no) other nodes. 4. ENGINEERING - Fiber/copper mesh networks are typically properly engineered for traffic-carrying capacity, QoS, latency, etc. Real-world wireless mesh networks are typically deployed in near-total ignorance of the Layer 1 (wireless layer) conditions. That's the great attraction (IMHO) of muni-mesh networking today. These networks are thrown up in the belief that they don't need any Layer 1 design or engineering
Re: [WISPA] Basic Mesh Theory
Brian, Exactly. You hit the nail on the head. The high noise levels combined with not enough license-free frequency space combined with unrealistically high traffic-handling expectations is going to doom most public Wi-Fi-based municipal networks to extinction while at the same time, polluting the license-free spectrum that a responsible, RF-smart, wireless ISP could have used to deliver reliable service to some subset (limited by the available license-free frequency space) of that city's citizens. Maybe the RF-smart WISPs will decide to reach out to their cities and make a case for working together to improve public wireless broadband access. If WISPs don't work with their city, then the city usually turns to a mesh vendor who will, in most cases, promise more than the technology (for the reasons you pointed out) can deliver. Even worse, large cities are turning to the Earthlinks and Googles of the world, as if the Earthlink or Google name is somehow going to bend physics and make these networks work. A big corporate name, as we all should know by now, does not change the way that RF propagates, or the way that interference and spectrum pollution slows down network performance. Thank you for sharing your thoughts, jack Brian Webster wrote: Jack, Let me jump in with some more thoughts on wireless mesh: I agree with you that RF engineering and RF limitations are not being fully considered in most mesh deployments. Most mesh designs I have seen are theory based and assume the full use of the unlicensed spectrum at hand. This will never be the case and therefore limits the overall capacity. I saw an RFP from the city of Miami Beach and they had done a pre-survey of the city and found the noise floor at 2.4 GHz at -70 db in most areas. Now how is one going to deploy a mesh network with the ability to overcome that? Typical answer is build more nodes closer to each other so these PDAs and laptops get enough signal. This ignores the fact that all of these close spaced nodes then create more noise for each other because they are mounted at a height where they hear each other. In high density nodes even having 2 hops will bring these networks to their knees. There is not enough spectrum to make it work and be able to load the network up. An 802.11b based system can not deal with the hidden node problem effectively enough. Even if you do have all the internode traffic on other frequencies at the high density placement required in most cities, the spectrum limits are still a big issue to have the channels to link all the nodes. I would still like to hear of a mesh network from any manufacturer that has been deployed and has a high density of users that are the kids of today. I want to see what bit torrent, VOIP and audio streaming do to a mesh in multiple hops. While we can make the argument that those services can be limited, that is only a band-aid approach as today's society is going to expect to be able to use these services in one form or another, it may take a while but it will be necessary. The cellular companies are already creating the expectation for this kids to be able to audio stream on demand. If someone has knowledge of a loaded mesh network please let me know. Don't get me wrong, I love the idea of mesh and wish it could work and want to see it work. It's just that I've been in ham radio since 1989 and was in to the packet radio technology, we as hams built networks where we dealt with all of these issues (I know it was only 1200 baud but the problems remain). There are two major problems in mesh from my viewpoint. One, if you have a carrier sense based collision avoidance system, you always have limited capacity because only one radio can talk at a time (part of the HDX problem). Two, if you do not have a carrier sense based system then you can overcome noise with a stronger signal. This causes cell site shrinkage or breathing and changes the coverage area. Most people deal with this by building transmitters closer to each other, problem is that there is limited unlicensed spectrum which is not enough room for most systems to deal with this. I really would like to see mesh work and hope to be proven wrong. There is a lot of promise in mesh implementations out there but until I have seen them under residential internet use loads I remain skeptical. Thank You, Brian Webster www.wirelessmapping.com http://www.wirelessmapping.com -Original Message- From: Jack Unger [mailto:[EMAIL PROTECTED] Sent: Monday, February 27, 2006 1:46 AM To: WISPA General List Subject: Re: [WISPA] Basic Mesh Theory Jeromie, You raise some good points... and here are some more differences between Matt's fully-meshed WIRED network example and the real-world conditions under which WIRELESS mesh networks are so often deployed today. 1) REROUTING - Only a node failure or a high peak traffic load would normally force
RE: [WISPA] Basic Mesh Theory
Brian, Exactly my thoughts. And I'm with you in the show me category. Brad -Original Message- From: Brian Webster [mailto:[EMAIL PROTECTED] Sent: Monday, February 27, 2006 11:01 AM To: WISPA General List Subject: RE: [WISPA] Basic Mesh Theory Jack, Let me jump in with some more thoughts on wireless mesh: I agree with you that RF engineering and RF limitations are not being fully considered in most mesh deployments. Most mesh designs I have seen are theory based and assume the full use of the unlicensed spectrum at hand. This will never be the case and therefore limits the overall capacity. I saw an RFP from the city of Miami Beach and they had done a pre-survey of the city and found the noise floor at 2.4 GHz at -70 db in most areas. Now how is one going to deploy a mesh network with the ability to overcome that? Typical answer is build more nodes closer to each other so these PDAs and laptops get enough signal. This ignores the fact that all of these close spaced nodes then create more noise for each other because they are mounted at a height where they hear each other. In high density nodes even having 2 hops will bring these networks to their knees. There is not enough spectrum to make it work and be able to load the network up. An 802.11b based system can not deal with the hidden node problem effectively enough. Even if you do have all the internode traffic on other frequencies at the high density placement required in most cities, the spectrum limits are still a big issue to have the channels to link all the nodes. I would still like to hear of a mesh network from any manufacturer that has been deployed and has a high density of users that are the kids of today. I want to see what bit torrent, VOIP and audio streaming do to a mesh in multiple hops. While we can make the argument that those services can be limited, that is only a band-aid approach as today's society is going to expect to be able to use these services in one form or another, it may take a while but it will be necessary. The cellular companies are already creating the expectation for this kids to be able to audio stream on demand. If someone has knowledge of a loaded mesh network please let me know. Don't get me wrong, I love the idea of mesh and wish it could work and want to see it work. It's just that I've been in ham radio since 1989 and was in to the packet radio technology, we as hams built networks where we dealt with all of these issues (I know it was only 1200 baud but the problems remain). There are two major problems in mesh from my viewpoint. One, if you have a carrier sense based collision avoidance system, you always have limited capacity because only one radio can talk at a time (part of the HDX problem). Two, if you do not have a carrier sense based system then you can overcome noise with a stronger signal. This causes cell site shrinkage or breathing and changes the coverage area. Most people deal with this by building transmitters closer to each other, problem is that there is limited unlicensed spectrum which is not enough room for most systems to deal with this. I really would like to see mesh work and hope to be proven wrong. There is a lot of promise in mesh implementations out there but until I have seen them under residential internet use loads I remain skeptical. Thank You, Brian Webster www.wirelessmapping.com http://www.wirelessmapping.com -Original Message- From: Jack Unger [mailto:[EMAIL PROTECTED] Sent: Monday, February 27, 2006 1:46 AM To: WISPA General List Subject: Re: [WISPA] Basic Mesh Theory Jeromie, You raise some good points... and here are some more differences between Matt's fully-meshed WIRED network example and the real-world conditions under which WIRELESS mesh networks are so often deployed today. 1) REROUTING - Only a node failure or a high peak traffic load would normally force a routing path change on a fiber/copper network. On a wireless mesh, routing path changes will also result from interference caused by other same-network nodes, interference from other networks, and interference from other wireless non-network sources. Routing path changes will also be caused by the movement of obstructions and other rf-reflective objects such as trees and vehicles. 2. CAPACITY - Fiber/copper networks typically start out with high-capacity (compared to wireless) full-duplex links. Wireless mesh networks start out with low-capacity half-duplex links. 3. CONNECTIVITY - Fiber/copper mesh network nodes have two or more paths to other nodes. Real-world wireless mesh networks may contain nodes that, in some cases (the traditional mesh definition not withstanding) only have a path to one other node. For example, obstructions may block paths to all but one (or even no) other nodes. 4. ENGINEERING - Fiber/copper mesh networks are typically properly engineered for traffic-carrying capacity, QoS, latency, etc. Real-world wireless mesh networks
RE: [WISPA] Basic Mesh Theory
As I recall the 60 GHz band has the problem of major attenuation because the oxygen molecules resonate at 60 GHz which means normal free space loss linear calculations have an anomaly at that range (which is why there is so much spectrum for unlicensed use). You make an excellent point about all the other spectrum available. The problem is we also have to look at the business case of these networks on these frequencies. Since you do not have any chipsets being produced in the millions for these bands there will never be an affordable solution here. Unfortunately (or fortunately) the only reason our industry has been one that could remotely be profitable has been because of the consumer devices that have been adapted due to the cost factor. Traditionally microwave radio equipment has been expensive and mostly due to the almost hand made process for each radio since demand is so low. It's the whole job without experience argument... Thank You, Brian Webster www.wirelessmapping.com http://www.wirelessmapping.com -Original Message- From: Jeromie Reeves [mailto:[EMAIL PROTECTED] Sent: Monday, February 27, 2006 3:04 PM To: WISPA General List Subject: Re: [WISPA] Basic Mesh Theory So how much spectum is needed? 24ghz is fairly clean, 60 ~ 70 is very clean. The problem is NOT the lack of spectrum. It is the lack of gear for the spectrum that would do well for mesh. Low range (oh noes low range!) high bandwidth and low noise. The short range will help with self interferance a lot. The 7ghz (yes, seven ghz of band space) is enough for 56 100mhz channels that are non over lapping channels with a 12.5mhz upper/lower gard band, then toss in cross pol. Ive seen some gear for this band but it is to costly right now for what it does. We need a SoC with 2 or 4 radios, 50~100mhz per radiowith a 2nd seup with 2 ~4 radios ad 200~400mhz per radio. Jeromie Jack Unger wrote: Brian, Exactly. You hit the nail on the head. The high noise levels combined with not enough license-free frequency space combined with unrealistically high traffic-handling expectations is going to doom most public Wi-Fi-based municipal networks to extinction while at the same time, polluting the license-free spectrum that a responsible, RF-smart, wireless ISP could have used to deliver reliable service to some subset (limited by the available license-free frequency space) of that city's citizens. Maybe the RF-smart WISPs will decide to reach out to their cities and make a case for working together to improve public wireless broadband access. If WISPs don't work with their city, then the city usually turns to a mesh vendor who will, in most cases, promise more than the technology (for the reasons you pointed out) can deliver. Even worse, large cities are turning to the Earthlinks and Googles of the world, as if the Earthlink or Google name is somehow going to bend physics and make these networks work. A big corporate name, as we all should know by now, does not change the way that RF propagates, or the way that interference and spectrum pollution slows down network performance. Thank you for sharing your thoughts, jack Brian Webster wrote: Jack, Let me jump in with some more thoughts on wireless mesh: I agree with you that RF engineering and RF limitations are not being fully considered in most mesh deployments. Most mesh designs I have seen are theory based and assume the full use of the unlicensed spectrum at hand. This will never be the case and therefore limits the overall capacity. I saw an RFP from the city of Miami Beach and they had done a pre-survey of the city and found the noise floor at 2.4 GHz at -70 db in most areas. Now how is one going to deploy a mesh network with the ability to overcome that? Typical answer is build more nodes closer to each other so these PDAs and laptops get enough signal. This ignores the fact that all of these close spaced nodes then create more noise for each other because they are mounted at a height where they hear each other. In high density nodes even having 2 hops will bring these networks to their knees. There is not enough spectrum to make it work and be able to load the network up. An 802.11b based system can not deal with the hidden node problem effectively enough. Even if you do have all the internode traffic on other frequencies at the high density placement required in most cities, the spectrum limits are still a big issue to have the channels to link all the nodes. I would still like to hear of a mesh network from any manufacturer that has been deployed and has a high density of users that are the kids of today. I want to see what bit torrent, VOIP and audio streaming do to a mesh in multiple hops. While we can make the argument that those services can be limited, that is only a band-aid approach as today's society is going to expect to be able to use
Re: [WISPA] Basic Mesh Theory
I haven't read your summary yet, but would like to chime in a bit on Mesh... When the DoD developed TCP/IP, they built it to be robust under war-time conditions. This means fault tolerant, rerouting, change-over, change-back. It would wonderful to hear the Mesh scientists (not sales people) describe what it is about mesh that gives it an edge over TCP/IP protocols, including their routing protocols. I'll read your notes with some interest, in the hopes they'll shed some light on this fundemental question. Else, historically mesh has been a crapola of marketing hype, generalizations, and I have it nailed crap intended to fuel someone's new car or new house, new sales organization - and not provide any real customer/network operator benefit. In my humble opinion. I personally have spoken to Microsoft's development leader on Mesh and had it explained that dozens of PhD's were working on Mesh solutions at MS. Ah, okay, I'm guess Motorola and 10 other companies are doing this as well. Has anyone deployed a TCP/IP network that's fault tolerant - along the lines of the DoD's intent for the network? Using 'Mesh' or otherwise. I'm all ear. Matt Liotta wrote: Attached is a quick rundown of basic mesh theory that I put together in light of the recent thread. It hasn't been peer reviewed or edited, which I would normally do before sharing publicly. But since I only wrote because of a thread on this list I figured I would just share it. Feel free to pick it apart. I do want to point out a couple of things though. First, this was written in a generic way only covering mesh as a theory. As written it can be applied to various transport technologies from fiber to wireless; though I do provide an example using wireless P2P links. Applying mesh theory to wireless P2MP or ad-hoc networks would require special coverage. -Matt -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Basic Mesh Theory
The internet is the largest mesh network in operation today. However, there is no comparison to internet routing and redundancy to that of private network routing and redundancy. The internet is so huge that smart routing decisions can only be made at the edge. With a private network, the size is generally manageable enough to make smarter routing decisions throughout. Take BGP for instance, which is used to dynamically manage routes on the internet. It can take anywhere from 4 to 10 minutes to fully resolve a route flap when a link goes down. Compare that with your average IGP, which takes only seconds to fully resolve a route flap. -Matt A. Huppenthal wrote: I haven't read your summary yet, but would like to chime in a bit on Mesh... When the DoD developed TCP/IP, they built it to be robust under war-time conditions. This means fault tolerant, rerouting, change-over, change-back. It would wonderful to hear the Mesh scientists (not sales people) describe what it is about mesh that gives it an edge over TCP/IP protocols, including their routing protocols. I'll read your notes with some interest, in the hopes they'll shed some light on this fundemental question. Else, historically mesh has been a crapola of marketing hype, generalizations, and I have it nailed crap intended to fuel someone's new car or new house, new sales organization - and not provide any real customer/network operator benefit. In my humble opinion. I personally have spoken to Microsoft's development leader on Mesh and had it explained that dozens of PhD's were working on Mesh solutions at MS. Ah, okay, I'm guess Motorola and 10 other companies are doing this as well. Has anyone deployed a TCP/IP network that's fault tolerant - along the lines of the DoD's intent for the network? Using 'Mesh' or otherwise. I'm all ear. Matt Liotta wrote: Attached is a quick rundown of basic mesh theory that I put together in light of the recent thread. It hasn't been peer reviewed or edited, which I would normally do before sharing publicly. But since I only wrote because of a thread on this list I figured I would just share it. Feel free to pick it apart. I do want to point out a couple of things though. First, this was written in a generic way only covering mesh as a theory. As written it can be applied to various transport technologies from fiber to wireless; though I do provide an example using wireless P2P links. Applying mesh theory to wireless P2MP or ad-hoc networks would require special coverage. -Matt -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
RE: [WISPA] Basic Mesh Theory
Hey Matt, It would be nice to see this in a word document or Text based so one could add comments to your work. DSJ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Matt Liotta Sent: Sunday, February 26, 2006 2:56 PM To: WISPA General List Subject: [WISPA] Basic Mesh Theory Attached is a quick rundown of basic mesh theory that I put together in light of the recent thread. It hasn't been peer reviewed or edited, which I would normally do before sharing publicly. But since I only wrote because of a thread on this list I figured I would just share it. Feel free to pick it apart. I do want to point out a couple of things though. First, this was written in a generic way only covering mesh as a theory. As written it can be applied to various transport technologies from fiber to wireless; though I do provide an example using wireless P2P links. Applying mesh theory to wireless P2MP or ad-hoc networks would require special coverage. -Matt -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Basic Mesh Theory
The file is attached as RTF. -Matt Dustin Jurman wrote: Hey Matt, It would be nice to see this in a word document or Text based so one could add comments to your work. DSJ *From:* [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] *On Behalf Of *Matt Liotta *Sent:* Sunday, February 26, 2006 2:56 PM *To:* WISPA General List *Subject:* [WISPA] Basic Mesh Theory Attached is a quick rundown of basic mesh theory that I put together in light of the recent thread. It hasn't been peer reviewed or edited, which I would normally do before sharing publicly. But since I only wrote because of a thread on this list I figured I would just share it. Feel free to pick it apart. I do want to point out a couple of things though. First, this was written in a generic way only covering mesh as a theory. As written it can be applied to various transport technologies from fiber to wireless; though I do provide an example using wireless P2P links. Applying mesh theory to wireless P2MP or ad-hoc networks would require special coverage. -Matt Title: Index of file:///Users/mliotta/Desktop/Basic Mesh Theory.rtfd/ Index of file:///Users/mliotta/Desktop/Basic Mesh Theory.rtfd/ Up to higher level directory TXT.rtf 6 KB 2/26/06 2:44:45 PM mesh.jpg 21 KB 2/25/06 7:18:06 AM ring.jpg 14 KB 2/25/06 7:09:12 AM -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
RE: [WISPA] Basic Mesh Theory
It didn't attach correctly. DSJ -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Matt Liotta Sent: Sunday, February 26, 2006 6:47 PM To: WISPA General List Subject: Re: [WISPA] Basic Mesh Theory The file is attached as RTF. -Matt Dustin Jurman wrote: Hey Matt, It would be nice to see this in a word document or Text based so one could add comments to your work. DSJ *From:* [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] *On Behalf Of *Matt Liotta *Sent:* Sunday, February 26, 2006 2:56 PM *To:* WISPA General List *Subject:* [WISPA] Basic Mesh Theory Attached is a quick rundown of basic mesh theory that I put together in light of the recent thread. It hasn't been peer reviewed or edited, which I would normally do before sharing publicly. But since I only wrote because of a thread on this list I figured I would just share it. Feel free to pick it apart. I do want to point out a couple of things though. First, this was written in a generic way only covering mesh as a theory. As written it can be applied to various transport technologies from fiber to wireless; though I do provide an example using wireless P2P links. Applying mesh theory to wireless P2MP or ad-hoc networks would require special coverage. -Matt -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Basic Mesh Theory
Matt, Are these actual costs? What is the coverage area? Thanks, Dawn Matt Liotta wrote: Attached is a quick rundown of basic mesh theory that I put together in light of the recent thread. It hasn't been peer reviewed or edited, which I would normally do before sharing publicly. But since I only wrote because of a thread on this list I figured I would just share it. Feel free to pick it apart. I do want to point out a couple of things though. First, this was written in a generic way only covering mesh as a theory. As written it can be applied to various transport technologies from fiber to wireless; though I do provide an example using wireless P2P links. Applying mesh theory to wireless P2MP or ad-hoc networks would require special coverage. -Matt No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.375 / Virus Database: 268.1.0/269 - Release Date: 2/24/2006 --- --- -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Basic Mesh Theory
I used street pricing for the radios in question, but certainly didn't cover pricing on any other items that would be required. Coverage area wasn't taken into consideration as it has no bearing on topology. -Matt Dawn wrote: Matt, Are these actual costs? What is the coverage area? Thanks, Dawn Matt Liotta wrote: Attached is a quick rundown of basic mesh theory that I put together in light of the recent thread. It hasn't been peer reviewed or edited, which I would normally do before sharing publicly. But since I only wrote because of a thread on this list I figured I would just share it. Feel free to pick it apart. I do want to point out a couple of things though. First, this was written in a generic way only covering mesh as a theory. As written it can be applied to various transport technologies from fiber to wireless; though I do provide an example using wireless P2P links. Applying mesh theory to wireless P2MP or ad-hoc networks would require special coverage. -Matt No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.375 / Virus Database: 268.1.0/269 - Release Date: 2/24/2006 --- --- -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Basic Mesh Theory
There is a very big difference from fiber mesh and wireless mesh. Wireless is classicly a bunch of HDX links where fiber is PtP links. Your example doesnt make it clear that the difference is what cause's 802.11[a|b|g] mesh suck and fiber/copper mesh's not suck. The solution is multi radio units that can select peers based on more then just essid (channel, hop count to the edge, packet loss, ect) Jeromie Matt Liotta wrote: Attached is a quick rundown of basic mesh theory that I put together in light of the recent thread. It hasn't been peer reviewed or edited, which I would normally do before sharing publicly. But since I only wrote because of a thread on this list I figured I would just share it. Feel free to pick it apart. I do want to point out a couple of things though. First, this was written in a generic way only covering mesh as a theory. As written it can be applied to various transport technologies from fiber to wireless; though I do provide an example using wireless P2P links. Applying mesh theory to wireless P2MP or ad-hoc networks would require special coverage. -Matt -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Basic Mesh Theory
My example used wireless P2P links, which has no inherent weakness over fiber P2P links from a topology point-of-view. It would appear you are falling into the same trap as others by forcing mesh to be something it is not. Mesh is just a network topology; no more, no less. Sure it is possible to come up with specific examples of wireless-based mesh networks being terrible ideas, but that doesn't mean there is anything wrong with mesh itself. I would argue that in almost all cases the topology is not what is at fault. -Matt Jeromie Reeves wrote: There is a very big difference from fiber mesh and wireless mesh. Wireless is classicly a bunch of HDX links where fiber is PtP links. Your example doesnt make it clear that the difference is what cause's 802.11[a|b|g] mesh suck and fiber/copper mesh's not suck. The solution is multi radio units that can select peers based on more then just essid (channel, hop count to the edge, packet loss, ect) Jeromie Matt Liotta wrote: Attached is a quick rundown of basic mesh theory that I put together in light of the recent thread. It hasn't been peer reviewed or edited, which I would normally do before sharing publicly. But since I only wrote because of a thread on this list I figured I would just share it. Feel free to pick it apart. I do want to point out a couple of things though. First, this was written in a generic way only covering mesh as a theory. As written it can be applied to various transport technologies from fiber to wireless; though I do provide an example using wireless P2P links. Applying mesh theory to wireless P2MP or ad-hoc networks would require special coverage. -Matt -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Basic Mesh Theory
Jeromie, You raise some good points... and here are some more differences between Matt's fully-meshed WIRED network example and the real-world conditions under which WIRELESS mesh networks are so often deployed today. 1) REROUTING - Only a node failure or a high peak traffic load would normally force a routing path change on a fiber/copper network. On a wireless mesh, routing path changes will also result from interference caused by other same-network nodes, interference from other networks, and interference from other wireless non-network sources. Routing path changes will also be caused by the movement of obstructions and other rf-reflective objects such as trees and vehicles. 2. CAPACITY - Fiber/copper networks typically start out with high-capacity (compared to wireless) full-duplex links. Wireless mesh networks start out with low-capacity half-duplex links. 3. CONNECTIVITY - Fiber/copper mesh network nodes have two or more paths to other nodes. Real-world wireless mesh networks may contain nodes that, in some cases (the traditional mesh definition not withstanding) only have a path to one other node. For example, obstructions may block paths to all but one (or even no) other nodes. 4. ENGINEERING - Fiber/copper mesh networks are typically properly engineered for traffic-carrying capacity, QoS, latency, etc. Real-world wireless mesh networks are typically deployed in near-total ignorance of the Layer 1 (wireless layer) conditions. That's the great attraction (IMHO) of muni-mesh networking today. These networks are thrown up in the belief that they don't need any Layer 1 design or engineering expertise and that this will allow for quick, widespread deployment. Last time I looked however, there was still no free lunch. I predict that the muni mesh networks that are thrown up today (Philadelphia will be a prime example, unless it's re-engineered correctly) will fail and fail miserably to meet the high expectations that have been raised like free or low-cost broadband for all. In addition, muni mesh networks today typically lack adequate traffic engineering and performance testing under load. The way that muni networks are being marketed today will likely lead to a black eye for the entire license-free wireless broadband industry within 18 to 24 months. I'm not saying that wireless mesh networks should never be used. There are certain (obstructed, short-link, low capacity) environments where they will be the best, most economical solution. I'm just saying that the false claims and marketing hype surrounding MOST (and let me repeat, MOST) of today's mesh networking claims, particularly mesh network nodes that contain just a single 2.4 GHz radio are going to come back to bite both the vendors and the cities that deploy these networks without sufficient wireless knowledge in the false belief that wireless mesh networks are just plug-and-play. Sorry about my rant, but other than a few responsible multiple-radio/multiple-band mesh equipment vendors, the current mesh marketing/hype environment is in a word - disgraceful. jack Jeromie Reeves wrote: There is a very big difference from fiber mesh and wireless mesh. Wireless is classicly a bunch of HDX links where fiber is PtP links. Your example doesnt make it clear that the difference is what cause's 802.11[a|b|g] mesh suck and fiber/copper mesh's not suck. The solution is multi radio units that can select peers based on more then just essid (channel, hop count to the edge, packet loss, ect) Jeromie Matt Liotta wrote: Attached is a quick rundown of basic mesh theory that I put together in light of the recent thread. It hasn't been peer reviewed or edited, which I would normally do before sharing publicly. But since I only wrote because of a thread on this list I figured I would just share it. Feel free to pick it apart. I do want to point out a couple of things though. First, this was written in a generic way only covering mesh as a theory. As written it can be applied to various transport technologies from fiber to wireless; though I do provide an example using wireless P2P links. Applying mesh theory to wireless P2MP or ad-hoc networks would require special coverage. -Matt -- 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 -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
