BigAir

Wireless communications devices provide considerable flexibility by sending signals over airwaves instead of over wires or fiber. However, sending signals over airwaves can create the opportunity for a security risk in the form of data interception. Using the following five techniques, which provide protection at the physical, network and application layers of the network, BigAir is able to provide a highly secure and robust system to keep out wireless eavesdropping and malicious user attacks.

The BigAir Networks security infrastructure has the following features:

1. Proprietary Wireless and Data Formats
   Unlike a WiFi based Wireless LAN such as 802.11b or 802.11a/g where the standard is "open," BigAir uses proprietary communications signaling and data-link protocols. Unless a customer has a BigAir Subscriber Unit, it would be almost impossible to intercept or spoof the wireless data streams.
   
   
2. Pseudo-random Transmission Scrambling and Encryption
   The proprietary signaling scheme used by BigAir pseudo-randomly scrambles the transmissions with one of over 500,000 scrambling sequences, thus increasing the difficulty of intercepting a transmission. Using another BigAir Subscriber Unit, it would take more than one year to search through all the scrambling codes. Encryption is also employed on every wireless link, typically at 128 bit.
   
   
3. MAC Address Authentication
   The BigAir Base Stations maintain a user-configurable and password controlled table of authorized BigAir subscriber unit MAC addresses. Subscriber units cannot talk to the network unless the BigAir Base Station Unit authenticates its MAC address and "adds" it to the network.
   
   
4. MAC Address Filtering
   The BigAir Subscriber Units are configured to filter the downlink traffic stream to prevent a BigAir Subscriber Unit from outputting traffic that is destined to another BigAir Subscriber Unit. The filtering restrictions can be based upon Ethernet addresses, VLAN addresses, or IP addresses. Only the BigAir network operations centre (NOC) can configure the filtering controls. This prevents unauthorized access of another user’s data.
   
   
5. Theft Protection
   BigAir Base Stations measure the distance of the connection to each BigAir Subscriber Unit. If one of the BigAir Subscriber Units is physically moved to another location, the BigAir Base Station will detect that the distance is different and will signal an alarm to the BigAir NOC. This protects against someone stealing a Subscriber Unit and using its valid MAC address to enter the network. Subscriber Units will not listen to a Base Station Unit unless they are "added" to the network via the Base Station Unit.