Mesh Networking makes audio (or video) files available anywhere, anytime. Each user device acts as a router/repeater for other devices. Hopping through other users reaches network access points not otherwise available. Hopping increases the coverage area by leveraging users as part of the network.
The Radiant system is being trialed by the BBC in the UK. It uses 28 or 40 ghz point to point radios. The main feed to the mesh is a 155mb ATM link. Each hub has 4 directional antennas so it can talk to 4 other sites. Range is 1-3 Km and the hubs are about $7,000. Trial customers in the 80-square-kilometre area will receive movies and music on-demand. The 28 GHz LMDS band has drawbacks; equipment is expensive, it requires an (FCC) license and range is short.
Community Networks often use Rob Flickenger’s open-source captive portal application, NoCatAuth (slide tutorial). Sharing Internet access with a next-door neighbor is one thing. Setting up a neighborhood network that can support dozens of users and provide reliable access for small businesses is more challenging. Mesh networking in the unlicensed band may provide an inexpensive alternative.
Mesh Networking Systems
Mesh networking provides non line-of-sight by relaying signals to neighboring nodes until a good backhaul connection is found. This technique allows low power (and 802.11a/b/g devices) to cover larger areas.
- Orlando-based MeshNetworks has been granted an experimental license for demonstrations nationally in both the 2.4 GHz and 5.7 GHz bands. Their solution works with 802.11 for voice, video and data at highway speeds. MeshLAN extends the range and robustness of existing WLANs by adding new Multi-Hopping and peer-to-peer capabilities to 802.11 cards. Mesh Network’s new ASIC will fit in PC Cards, Compact Flash and Mini-PCI. Mesh Networks uses QDMA and features built-in geo-location with “smart” antenna technology. They deliver up to 6 Mbps of broadband data to every subscriber, “hopping” through neighborhood cells.
- CoWave’s MeshCast uses two 5 MHz spectrum bands in up to 8 sectors with 6 mbps delivered to an indoor, self-installed unit. It provides broadband network access at multi-megabit rates and connects to the Ethernet or USB port of the computer. The Base station aggregates traffic for all the sectors and connects to the service provider backbone. The company plans to develop gear for all bands below 6 GHz, and expects to begin shipping MestCast equipment for systems deployed in the 1900 MHz (PCS) band in the fourth quarter.
- Wave Wireless is shipping industrial strength mesh networking products for the 2.4 GHz band. They are using PacketHop technology developed at SRI, using their Mobile Ad-hoc Networks (MANET) mesh protocol. PacketHop reduces the data overhead of mesh networking although each node must remain “on” to pass the signal.
- Mobile Mesh (FAQ), is a suite of non-proprietary protocols and Linux based software tools developed at Mitre that provide a mobile adhoc networking capability.
Non-Mesh Systems (using MMDS)
Multipoint Multichannel Distribution Services (MMDS) can use more power but require licensed frequencies. MMDS systems are licensed to operate on sixteen (16) channels – each 6MHz wide – with 200 MHz of spectrum (between 2.5 GHz and 2.7 GHz). It was originally conceived as “wireless cable” but later was allowed to provide two-way data for “wireless internet”. MMDS systems are often deployed in a full 360 configuration, and powered to cover the maximum distance allowed by the FCC (35 mile radius). In practice more than one base station is often required due to interference.
Sprint paid $448.8 million for American Telecasting MMDS licenses covering a potential 10 million households in Denver, Portland, Ore., Seattle and Las Vegas. Sprint also got four (6 MHz) ITFS channels in Portland, and other communities. Sprint’s spectrum portfolio includes more than 1,100 channels in 90 markets. Those agreements allow for two-way, cellularized, broadband voice, video and data services.
Other licensed Frequencies
The 2150-2162 MHz are allocated to the original MDS band while the 2.3 GHz, Wireless Communications Service has 30 MHz of spectrum from 2305 to 2320 MHz and 2345 to 2360 MHz. Higher up, the Local Multipoint Distribution Service (LMDS) uses 27.35 – 28.35 GHz, 29.1 – 29.25 GHz and 31.0 – 31.3 GHz freqency bands. Broadband auction bandplans show who’s got what. Search the FCC database for licenses in your area.
Name of the Game
Delivering 3G-like services to “hot spots” or individual laptops is the name of the game. Several companies have announced national “hot spot” initiatives including HP, Toshiba and IBM. MMDS could tie them together. MMDS competitors for mesh networking include:
- NextNet Wireless: Enables MMDS service providers to deliver low-cost, indoor services using an OFDM-based, portable, self-installed unit.
- Netro: Acquired AT&T Wireless’ fixed wireless assets and uses its AirStar and Angel technology for N-LOS, COFDM.
- Arraycomm: Uses MMDS and Adaptive MultiBeam OFDM with Time Division for two-way voice as well as data to portable CPE. It’s being tested in Australia.
- Flarion Uses MMDS (2.5GHz) and is testing service for Nextel using the 2.1 GHz band. They are developing a chip and PC card for mobile broadband.
- Beamreach: Uses Adaptive MultiBeam-OFDM in the MMDS band. Verizon is an investor and may do trials.
- IP Wireless uses the MMDS and TD-CDMA modulation, basically a modified U-MTS “3G” system for NLOS “wireless DSL”. The palm-sized, self-installed CPE unit is operational in Montana and Hawaii. Sprint is trialing it, too.
The 2.4/5.8 GHz Band (Meshed and N-LOS)
The unlicensed 2.4/5.8 GHz band might feed a Community LAN “hot spot”. Can’t get “wireless DSL” directly? Then try an unlicensed mesh network. It might give you “wiggle room” to the nearest hub. Intel and Microsoft are working on “soft Wi-Fi” which could make peer-to-peer networking more common.
- Aperto’s 5.8 GHz PacketWave base station and subscriber units provide up to 8 Mbps to over 3,000 students and 267 classrooms, in the Sacramento school district.
- Alvarion has a variety of industrial-strength wireless solutions in its Breeze Access line for voice, data and IP services.
- Iospan Wireless uses two transmit antennas at the base station and three receivers at both ends of its links. Iospan’s multiple antenna technology is known as MIMO, for multiple-input, multiple-output. At 6 km, over 6 Mb/s down and 4 Mb/s up is possible. Iospan’s multiple antenna enhancements of the OFDM modulation technique are being standardized in the IEEE 802.16 Working Group on Broadband Wireless Access Standards.
- Westerm Multiplex’s Tsunami 100 Mbps 5.8 GHz provides connections for distances up to 18 miles. Their Tsunami Multipoint enables up to 60 Mbps per base station, and up to six base stations per hub site. List pricing for subscriber units ranges from $1,295 for a 20 Mbps model to $2,995 for a 60 Mbps model. Western Multiplex’s highest-capacity wireless system, the Lynx OC-3 is designed to provide 155 Mpbs of bandwidth for distances of up to seven miles
- Cirronet’s WaveBolt supports up to 960 subscribers (point to multi-point), typically within a three to five mile range. The 5.8 GHz WaveBolt system uses frequency hopping spread spectrum (FHSS) technology
- Motorola’s Canopy has a pt-to-pt range of about 10 miles. Cascade Networks uses Canopy for their wireless interent in Vancouver, Washington.
- NextWeb: Provides broadband Internet access, data security solutions and web hosting in the 5.8 GHz band for public and private sector clients throughout the San Francisco Bay area and Silicon Valley. Base stations on high-rise building rooftops use wireless access units with sectorized directional antennas. Each unit typically allows a three-mile range, giving a fully provisioned base station coverage over a 28 square mile area. Up to 250 subscriber units can be deployed per sector, with user throughput of 25 Mbps, dynamically allocated among users, upstream or downstream.
- Navini Networks: Can use the unlicensed 2.4 GHz band, with CDMA to deliver DSL speeds using a small, inexpensive wireless device. Sprint is conducting a trial and Intel is a partner incorporating the technology in its 802.11b Access Point.
- Nokia’s Mesh Network: Using the unlicensed 2.4 GHz band, Vista Broadband uses the system to deliver 2 Mbps for $50/mo.
- Open AP: Although experimental, Instant 802 (list archives) “burns” an AP with a Linux system creating an inexpensive, meshed networking system. It uses mostly obsolete Access Points but rumor has it that newer commercial boxes will soon be available.
Wireless software maker iPass will provide its roaming software for free. About eight equipment makers, including Cisco Systems, and eight wireless Internet service providers have been using its software for roaming between different “hot spots”. The Wireless Ethernet Compatibility Alliance (WECA) may take at least another year on their roaming standard, which led to the creation of an upstart group called Pass-One, which has just begun working on a proposed roaming standard. The iPass Network architecture includes security architecture, with VPN, firewall, and authentication systems, the iPassConnect client, a billing system and the proprietary iPass RoamServer and NetServer, which they claim supports 2,000 corporate customers on 160 unique networks.
Optical Mesh Networking
There are several compaines working on optical mesh networks which require no frequency license from the FCC. They are STRICTLY line of sight but may offer advantages. Companies with FSO equipment include Canon (which has adapted camcorder anti-shake electronics to it’s gear, Terabeam, based in Kirkland, Washington, SONAbeam (BC), and San Diego companies AirFiber, LightPointe and Optical Access. Cisco’s COMET brings together SONET, DWDM, Ethernet, MESH and storage to create scalable, service-rich networks.
Meanwhile, Free Networks.org reports on a wireless network in Prague that uses 802.11b – and OPTICAL NETWORKING. Their homemade optical network gear, the optical equivalent of a Pringle can antenna, uses common parts like LEDs for 10Mbps links.
Wireless LAN resources for Linux as well as software like PacketHop and Mobile Mesh may be downloaded. CMU Projects and the journal, SIG Mobile have many ideas. Wireless campus networks include CMU’s Wireless Andrew and PSU’s PubNet. Portland State Professors, James Binkley and Suresh Sing, teach classes dealing with “Wireless Peer to Peer Computing”. Perhaps PSU’s Intelligent Transportation Systems Lab could apply wireless peer to peer in the field. UCSD’s CyberShuttle uses 802.11b inside the bus while 1XEV-DO provides a 2.4 Mbps backbone.
Free the LMDS Band
The solution for unbiquitous broadband is simple; remove the license restrictions on the 28 GHz band for “wireless cable”. Imagine 100 Mbps wireless using LMDS for the backbone, unlicensed 60 GHz (at 622 Mbps) from pole-top distribution points and Ultra Wideband for “wireless Firewire” around the house.
With 1 GHz of bandwidth “freed” and an open marketplace, the decimated LMDS industry could be salvaged. At 28 GHz, far more bandwidth is available then on the 802.11b band (85 MHZ) and 802.11a band (300 MHz). The IEEE 802.16 committee has approved a package of standards for the LMDS band but without a viable LMDS market it is going nowhere.
The FCC will probably allow RBOCs to run monopoly DSL services without “equal access”. Then the cost of DSL and cable broadband will likely rise. The broadband market will move to the far East. The United States has dropped from 5th place to 10th place in broadband deployment and may continue to spiral down.