ZigBee-over-Ethernet Bridge allows to connect two or more wireless ZigBee sub-networks to a single network (LAN, Internet, etc.). Most networking equipment has 10/100 T-Base Ethernet interfaces. This makes it especially easy to use the bridge for connecting the wireless segments of the ZigBee network over the Internet or other IP networks. In particular, many DSL access routers, cable modems, SOHO routers, etc., have Ethernet ports to which the bridge can be connected.

ENCAPSULATION USED FOR CARRYING ZIGBEE DATA:

The NWK packets are encapsulated into UDP (over IPv4) packets before being sent over the Ethernet. The reason for this is to increase the flexibility of use: an IP packet can be forwarded across any other network including the Internet.

AUTO-CONFIGURATION AND NEIGHBOR DISCOVERY:

A bridge must be assigned an IP address in order to be able to send and receive IP packets as described above. The designers have strived to achieve a balance between simplicity and flexibility of IP address configuration, so the resulting algorithm is as follows. Upon the start-up, the bridge broadcasts DHCP requests. If there are replies, it uses the reply with the highest priority to obtain its IP address, the net mask, the default gateway, and the DNS server. If no reply was received before the configured timeout expires, the auto-IP procedure is used.

PHYSICAL AND RADIO-ELECTRICAL CHARACTERISTICS:

The bridge can be powered either by an external AC/DC adapter providing 5 V output, or by Power over Ethernet (PoE). An optional module located in the same housing is needed for using PoE.

The bridge has backup batteries (4хAAA, 1.2 V, 600 mA·h) allowing for limited operation of the network in case of black-out in the mains. Depending on the traffic, the battery can last from 30 minutes (if non-stop radio transmission takes place) to many hours. After the brown-out condition of the battery is detected, the bridge goes to the hibernate mode, preserving the logs and the settings. The main foreseen usage of the battery operation is to make it possible for the monitoring and control network to communicate the fact of power loss in the mains to all the interested nodes. The reaction to such notification is user-specific, but generally the system should prepare to a communication breakdown.

ZIGBEE-OVER-ETHERNET BRIDGE CHARACTERISTICS: