All wireless CSMA/CA and 802.11 radios assume that all nodes have carrier sensing (detection). This means that all the radios in a system can “hear” each other’s radios signals and not transmit if others are currently transmitting. This is easily achieved in an in-building installation but not able to be achieved in typical out-door point-to-multipoint environments. RTS/CTS is a concept that has been included in 802.11 but does not solve this problem. When an RTS is sent from a remote satellite station to the central base station it will corrupt any data that other satellite stations are currently sending. This results in unnecessary packet loss and multiple re-transmissions. In a very lightly loaded network this may not be a problem, but as soon as the network becomes more then approximately 20% loaded, collisions resulting from hidden nodes greatly increase and the performance dramatically decreases.

The dynamic polling algorithm used in the Campus Software set of features sense when the network is under heavy load and automatically switches from a contention based network (i.e. the standard CSMA/CA situation) to a modified round-robin polled network. As the network continues to increase the polling method becomes more like a standard round robin polling scheme.

Satellite systems cannot be added to the list of Authenticated systems that the Base Station will communicate with, unless they first pass a MD5 based CHAP (Challenge Response Protocol). The base station periodically sends random challenges to all new satellite systems wishing to join in the “Cell”. Only if the satellite responds with the proper key will the base allow it to communicate. The key used is 128 bits long and is derived from a simple 64 byte ASCII pass-phrase. CHAP type protocols were chosen because they are immune to “repeat” attacks.

Most wireless and 802.11 radios have large inter-packet gaps as compared to Ethernet. This inter-packet gap from any given stations point of view is also increased in a point-to-multipoint installation. This is due to the medium being busy with other station traffic and also the polling and acknowledgment overhead. As part of the Campus Software features many packets can be combined (compressed) into a super-frame for transmission on the wireless link. This data compression technique when combined with polling greatly increases overall system throughput. The exact amount of throughput increase depends upon the typical packet size, number of satellites in the system, quality of the radio links, etc. In the best case (i.e. one base and one satellite this compression increases average throughput in a WaveLAN-1 radio environment by 2 times. In a WaveLAN/IEEE based system the increase in performance is calculated to be approximately 4 times.

Our studies have shown that 66% of all Internet packets are less then 100 bytes long. WaveLAN-1 will transmit 100 byte packets at approximately 1.1Mbits/sec. When these packets are combined into a 2Kbyte super-frame they can be transmitted at an effective rate of 1.85 Mbits/sec. For WaveLAN/IEEE the 100 byte packets are transmitted at approximately 500Kbits/sec. When compressed into a 2K byte super frame these packets can be transmitted at 1.8Mbits/second.

Several software data encryption algorithms are available including 56 bit DES, 128 bit IDEA, 128 bit Blowfish, and 128 bit RC4 and also custom encryption algorithm. All of these algorithms can be limited to a 40 bit key for non-USA export. The key is specified in a easy to configure 64 byte pass-phrase and then reduced to the proper size key and MD5 hash algorithm.

The network service provider can limit (throttle) the bandwidth that each customer is allowed to us. This is accomplished in the Wireless Satellite stations or bridge/routers.

The RF signal level, noise level and signal quality for each and every wireless connection is continuously monitored and statistics kept in each wireless bridge/router. These can be queried using SNMP.

Any wireless path can be tested for RF signal level, noise level and signal quality using a built in remote Point-to-Point testing feature. Support for a “rigorous” test is included.

Each wireless bridge/router box contains the ability to allow the operator to analyze the maximum user throughput on any Internet path. This is accomplished by completely loading down that data path, with a given packet size, for a few seconds and reporting the statistics gathered via SNMP. This is an valuable tool to help the installer/operator properly analyze the users actual performance for any given link. This tool is and extension of the popular Unix “pingflood” program and will work over any Internet connection.

An optional RFC compliant classless IP router with RIP 1 and 2 capability is provided. Routing is an important feature to reduce unwanted traffic on wireless links and manage IP addresses.

All protocols can be bridged through the wireless system. In addition any Ethernet protocol can be filtered (blocked) by the bridge to help reduce unwanted wireless traffic.

For users who wish to only use one PC (Windows 95/98/NT) as a Campus Satellite station a special NDIS driver is provided. This enables the user to install the WaveLAN card (and optionally a directional antenna) into their PC and gain access to the Campus based infrastructure.

Standard roaming protocols are supported and work in conjunction with Campus Software. For most building-to-building installation there is no need for roaming capability, however, if the satellite computer is a Laptop with a Campus/NDIS driver then that Laptop can roam between base stations while it is also taking advantage of the Campus feature set.

Each PC is connected to the Wireless Cell in the same manor as if they are connected to a wired LAN. No "dialing up" required.

When NDIS based Campus Satellites are being used the ISP looses control of who can “authenticate” and communicate with the wireless base station. In this scenario an ISP can elect to use a standard Radius server to provide Authentication and Accounting information for each customer’s PC. This will provide the ability for the ISP to terminate customers who have not paid their bills or to run a monthly special where certain customers can get higher bandwidth allocated to them.

To support Voice-Over-IP and Video Conferencing, quality of service algorithms (priority queuing) are being implemented. RSVP and other standards will be supported.

In order to expand the currently limited IP addresses a Network Address Translation function is being implemented.

Standard TCP/UDP/IP Firewall Functions are being ported over from a related product for use in the Wireless bridge/router product. These function provide the ability to limit access to the customers LAN’s on a TCP/UDP port (function) basis. As an example, a customer could setup this wireless bridge/router with such capability as allowing Web access to only a specific set of computers, while allowing e-mail to others and prohibiting all other protocols.