Architecture
The Aprisa SR+ Architecture is based around a layered TCP/IP protocol stack:
• Physical
Proprietary wireless
RS-232 and Ethernet interfaces
• Link
Proprietary wireless (channel access, ARQ, segmentation)
VLAN aware Ethernet bridge
• Network
Standard IP
Proprietary automatic radio routing table population algorithm
• Transport
TCP, UDP
• Application
HTTPS web management access through base station with proprietary management application
software including management of remote radios over the radio link
SNMPv1/2/3 for network management application software
Product Operation
There are three components to the wireless interface: the Physical Layer (PHY), the Data Link Layer (DLL)
and the Network Layer. These three layers are required to transport data across the wireless channel in the
Point-to-Multipoint (PMP) configuration. The Aprisa SR+ DLL is largely based on the 802.15.4 Media Access
Control (MAC) layer using a proprietary implementation.
Physical Layer
The Aprisa SR+ PHY uses a one or two frequency half duplex transmission mode which eliminates the need
for a duplexer. However, a Dual Antenna port option is available for separate transmit and receive antenna
connection to support external duplexers or filters (half duplex operation).
Remote nodes are predominantly in receive mode with only sporadic bursts of transmit data. This reduces
power consumption.
The Aprisa SR+ is a packet-based radio. Data is sent over the wireless channel in discrete packets / frames,
separated in time. The PHY demodulates data within these packets with coherent detection.
The Aprisa SR+ PHY provides carrier, symbol and frame synchronization predominantly through the use of
preambles. This preamble prefixes all packets sent over the wireless channel which enables fast
Synchronization.
To Next Page
Loading...
