Specifications

1-20 800 MHz System Planner R4-11-4G
PRIVATE DATATAC SYSTEM PERFORMANCE
Capacity Issues
1.7.1.4 RNC Capacity
RNC capacity, using the standard message profile, is 100K mph. This
capacity equates to approximately five fully-loaded RD-LAP 19.2 kbps radio
channels, or approximately nine fully-loaded RD-LAP 9.6 kbps radio
channels using radio modems with 5 ms transmitter turn-on (TTO) time.
1.7.1.5 Radio Channel Capacity
The radio channel capacity study for the standard message profile shows that
the IB radio channel is the limiting factor. The efficiency of the IB channel
contention method directly relates to the key parameters of message length
and radio TTO time.
1.7.1.6 Mobile Computer Messaging Capacity
The mobile computer message capacity consists of the radio modem capacity
and the mobile computer application’s ability to process messages.
The capacity of a radio modem is the number of messages it can send and
receive within an hour, which is 1,000 mph, using the standard message
profile. A Private DataTAC radio modem can send or receive data messages,
but not simultaneously.
The radio modem prioritizes outbound messages over inbound message if
both are encountered simultaneously. Radio modems cannot send outbound
messages if they are receiving an inbound message. The radio modems are
designed to wait until a message is successfully sent or retries (up to four)
are exhausted. Radio coverage reliability can have an impact on modem
message capacity.
1.7.1.7 System Response Time
System response time during typical and peak system use is the most
apparent user concern. A transaction is a user-initiated message and the
subsequent response(s). The time it takes to complete a transaction is a
combination of mobile computer and host processing delays and radio
system delays. Excessive delays can reduce operation efficiency and
effectiveness which can be frustrating to the user.
The major areas that impact system response times are:
• Application hosts
• Host systems
• Private DataTAC network(s)
• Mobile computer and its application(s)
• Number of mobile computers using the channel
Message delivery delay and response delay specifications are expressed
statistically. Two common statistical methods are average and 90th percentile