1. Introduction
SpaceLink Home Gateway
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Chapter 1 - Introduction
Wireless Operation
The SpaceLink Home Gateway will operate as a MAC layer learning bridge
and forward packets between wireless mobile clients and the Ethernet
network.
A wireless LAN that uses the SpaceLink Home Gateway generally consists
of one or more 802.11b Access Points and one or more wireless mobile
clients that have an 802.11b adapter installed.
The SpaceLink Home Gateway maintains a table of MAC addresses, which
it has learned are located either on the Ethernet network or on the radio
network by monitoring the source address of packets it receives. For
example, if the SpaceLink Home Gateway receives a packet over its radio,
it creates an entry in its table for the node that sent the packet and labels the
entry as a member of the radio network. The SpaceLink Home Gateway
removes an entry from the table after five minutes of inactivity.
When the SpaceLink Home Gateway receives a packet from the Ethernet
network, it compares the packet’s destination address with the node
addresses listed in its table. If the packet’s destination address is not in the
table, the SpaceLink Home Gateway will forward the packet to the wireless
mobile clients. If the packet’s destination address is listed in the table as a
member of the radio network, the SpaceLink Home Gateway will forward
the packet to the wireless mobile clients. If the packet’s destination address
is listed in the table as a member of the Ethernet network, the SpaceLink
Home Gateway will not forward the packet to the wireless mobile clients.
The SpaceLink Home Gateway applies the same principles to determine if
a packet received over its radio should be forwarded to the Ethernet network.
The SpaceLink Home Gateway forwards all broadcast packets to wireless
mobile clients. Given this, the SpaceLink Home Gateway can only support
250 nodes.
The speed available to wireless mobile clients depends on the amount of
information that each client exchanges with the network because the 11
Mbps wireless bandwidth is shared will all wireless nodes.
