RapidLink Mesh Networks
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Answers to your questions about RapidLink mesh networking products and systems.

General Questions

Q. What is a RapidLink mesh system?
A. RapidLink is an advanced, ad hoc, wireless mesh networking technology that can be instantly deployed, is self-configuring and self-healing. RapidLink uses open standards-based mesh architecture to create reliable, secure, high performance wireless data networks that can be sized, customized and configured to meet the specifications of each individual project.

Q. What are the benefits of using a wireless mesh networking system?
A. A wireless mesh network provides a secure information grid for use virtually anywhere. Users can transmit data instantly, intelligently, and securely over a highly redundant wireless network consisting of autonomous routers or nodes. The network can be deployed on land or sea, in rural or urban environments, to and from fixed or temporary sites, and even in remote or inhospitable terrain.

Q. What advantages do RapidLink systems have over other networking systems?
A. RapidLink systems are economical and easy to deploy because wireless mesh architecture eliminates the need for fixed infrastructure, typically the most costly and time consuming part of a communications network. In addition, RapidLink systems are self-configuring and self-healing so they can be instantly deployed and remotely monitored and maintained. RapidLink does not have a pre-defined box but can be configured, modified or expanded on an ad hoc basis. RapidLink products provide secure data transmittal and are highly resistant to failure.

Q. How does a mesh network work?
Each node in a mesh network is a wireless router that connects to every other node in the system by forwarding data to neighboring nodes until the data reaches its final destination. This wireless peer-to-peer forwarding of data eliminates the need for wired networking infrastructure, greatly reducing the cost and time to deploy a network.

Q. What is a RapidLink router?
A router (also called a node, station or pod) is a device that forwards data to its neighbors in a mesh network. RapidLink routers transmit data instantly, intelligently, and securely over the wireless network consisting of any number of autonomous nodes that, together, make up the data system.

Q. Is a RapidLink mesh network secure? Can it be hacked or sabotaged?
RapidLink networks are secured by AES and Triple DES, both of which meet the security requirements of the most demanding applications of governmental, law enforcement, health, security and financial market users. Triple DES, which is a variation of the Data Encryption Standard (DES) developed by IBM and subsequently adopted as a national standard, has proven reliability and is widely used because it is easy to modify existing software to use it. Concentris’ implementation of AES and Triple DES encryption has been validated by FIPS 140-2.

Q. How safe are the nodes in a RapidLink system? Can they be tampered with, damaged, or destroyed?
A. RapidLink nodes are sturdy, rugged, and durable. They are designed to operate in severe outdoor environments so that, once deployed, the system is virtually indestructible.

Q. How does a RapidLink system configure itself and heal itself?
The distributed and redundant nature of peer-to-peer mesh architecture eliminates single points of failure in the system. The RapidLink network continuously monitors for changing network topology and disruptions, and seamlessly determines the optimal wireless pathways for data. If a path is no longer available, it takes the next best alternative route.

Q. What are some likely uses for a RapidLink system?
RapidLink networks are ideal for situations where conventional networking techniques are impractical or cost prohibitive, including difficult, critical or ad hoc applications such as first-response disaster and rescue missions, homeland security applications, law enforcement, mobile field offices, fleet and convoy communications, and facility surveillance networks.

Questions about integrating a RapidLink system with other platforms

Q. How does the RapidLink system interface with existing software on a wired network?
RapidLink is an IP network based transport system. Any software system that operates over a standard Ethernet/IP network can interface with the RapidLink family of products with no special interface adaptor or other special equipment.

Q. How does a peripheral device, like a printer or a PDA, interface with the RapidLink network?
Simply connect them to a node via an access point or the Ethernet port.

Q How many access points can be linked to one radio?
Up to 250 access points can be linked to a single RapidLink node if a switch is attached to its Ethernet port. However the total data capacity of all the access points must be less than the capacity of the single RapidLink node. Concentris offers a node that has an integrated access point.

Q. Does a RapidLink mesh network support a billing system for e-commerce?
Yes. Many companies provide billing, authorization, authentication and other e-commerce systems that are compatible with the RapidLink technology. LOK Technologies, maker of AirLOK systems, is one such company.

Networking Security Questions

Q. How do you ensure privacy on the LAN using a RapidLink system?
Most Internet sites are encrypted to prevent unauthorized inspection of traffic. Additionally, Concentris tunnels traffic securely across the mesh using SSL, AES, and Triple DES.

Q. Does a RapidLink network require anti-virus immunization? Why or why not?
No. Antivirus is handled by the operating system of the host PC, not the network.

Questions about Technical Specifications

Q. What are the benefits of the OLSR protocol?
Optimized Link State routing (OLSR) protocolis an open protocol that is widely used and is being actively extended by a community of users. OLSR is a table-driven pro-active approach to mobile ad hoc network (MANET) routing that delivers real-time understanding of the network topology. OLSR operates by updating and maintaining information in tables. As its name suggests, OLSR optimizes the link-state scheme to diffuse topology information. In a classic link-state algorithm, link-state information floods throughout the network. OLSR modifies this approach to run in wireless multi-hop scenarios so routing updates are optimized to preserve bandwidth. The optimization is based on a technique called multi-point relaying that creates a multi-level hierarchy that decreases routing update overhead and enhances scalability to large numbers of nodes.

Q. What is the data rate for RapidLink nodes?
The data rate is about 10 milliseconds per jump. Streaming video, at about 500 milliseconds, does not have noticeable latency.

Q. What is the throughput for a RapidLink network? What are the variables?
Throughput averages about 10-15 Mbps depending on the number of nodes in the system and the distance between them. As more nodes are added to a system, the data rate gets higher (slower); as the distance between nodes increases, the data rate also increases.

Q. It appears that in a chain topology where a single node sends information to a node at the end of the chain, the throughput approaches 1/7th of the maximum data rate. So for a 54 Mbps 802.11g, you would expect about 7.7 Mbps throughput to the last node. Is this actually the case?
Yes, the denser the mesh becomes, the more congestion there is and bandwidth may suffer as a result.

Q. Why did Concentris choose to operate in the 5.4 Ghz frequency vs. the 2.4 Ghz frequency?
RapidLink products can operate in either band. Concentris’ standard configuration is in the 5.4 Ghz frequency because it is less crowded, there is less interference, and the channels are spaced better in this band. However, if an implementation calls for a RapidLink system to operate in the 2.4 Ghz frequency, this can be easily accommodated.

Questions about Applications

Q. In a location where high electric voltage is passing through the property, will this affect the wireless equipment / signal?
No. However it is advisable to keep nodes about 15 feet away from the electrical line.

Q. If several locations have Concentris mesh networks, can these be linked over a leased line connection?
Yes. RapidLink systems can be expanded, extended and reconfigured. The RapidLink network automatically locates and assimilates new stations, proactively configures the network, and provides seamless coverage. The station nodes operate unattended, begin forwarding data instantly, and may be positioned or dropped virtually anywhere.

Q. Does Concentris have any plans to operate in the public safety band? If so, when will these devices be available?
If a project calls for RapidLink products that operate in a different frequency, RapidLink accommodates the need. However, RapidLink’s standard models are all in the 802.11 frequency range.

Power Supply Questions

Q. Are RapidLink products self-powered or do they require an external battery source?
RapidLink nodes may be either externally powered, with lithium ion batteries or via an AC or Ethernet connection, or self-powered with a solar panel.

Q. For non-solar powered nodes,what type of battery is used? What is the battery current draw? Supply voltage?
CSL is considering Ni-Cad or Ni-MH batteries as they have good capacity and are lightweight, albeit a bit more expensive. The battery draw is about 500ma. The life span of each charge is a function of the size of battery. Supply voltage is generally between 8 and 30v dc.

Questions about Concentris Systems

Q. Where are RapidLink networks in use currently?
Concentris References: GTSI (large government reseller), REMAS.gov (US Dept of Defense communications contractor). Systems that have used either CSL technology or that of our previous companies: Maui International Airport, Los Gatos Toll House Hotel, Outrigger Hotels, Starwood Hotels.