User's Manual

605-0000-706 ProST Installation User Guide-Rev E
10
ProST Protocol Stack
The figure below displays a block diagram of the ProST's network architecture, designed as a
hierarchy of protocols (i.e. protocol stack) implemented in the communication network.
Theory of Operation
For basic operation, the ProST requires no initial configuration--simply plug and play. Configuration
is automatically performed over the air by the BS. The ProST is preconfigured by the operator at the
BS (using Netspan) with service flow parameters such as the maximum information rate, the
committed information rate, the maximum latency, and maximum jitter. These configuration
parameters are stored in Netspan's database corresponding to the ProST's MAC address.
Before any communication between ProST and BS can occur, the ProST must be positioned in a
location that provides sufficient RF reception.
To join a network, the ProST needs to perform a few tasks. First, the "Network Entry" process
(defined in 802.16-2004) begins with the ProST scanning for a downlink (DL) signal from the base
station, and then synchronizing to the DL channel. Thereafter the ProST can start the process of
initial ranging, which alerts the BS to the presence of the ProST and establishment of management
connections to obtain basic and primary management connection IDs (CID) from the BS. After the
CIDs have been obtained, the ProST commences authorization and key exchange. In the final stage,
the ProST registers at the base station before obtaining the IP address, time of day and the
configuration file.
During Network entry, the ProST sends the BS its MAC address. The BS then accesses Netspan's
database (via SNMP) and checks whether the ProST's MAC address appears in the DB. If it locates
the MAC address, the BS retrieves all the ProST's configuration parameters (service flows) from the
DB and downloads them to the ProST device.