3
DH-PFM88X is able to work in complicated and changing environment: working temperature ranges
from -30
℃
to 70
℃
, while working humidity ranges from 5% to 95%. DH-PFM88X keeps relatively high
throughput rate in all kinds of harsh environment for a long time, such as thunderstorm, high temperature
and high humidity, low temperature and low humidity.
1.2
Overview of TDMA Technology
At present, most remote Wi-Fi network bridge products have developed from 802.11 WLAN
technology. Built-in TDMA operating system integrates TDMA, flexible configuration of
5M/10M/20M/40MHz bandwidth, rate control and ACK overtime automatic adjustment technologies, and
it is known as an ideal remote Wi-Fi access product. TDMA effectively solves hidden node problem that
perplexes large point-to-multipoint WLAN. Flexible configuration of 5M/10M/20M/40MHz bandwidth
realizes balance between scarce wireless bandwidth resource and complicated working scenes: narrow
wireless bandwidth configuration is used when there are less idle wireless channels and single user
doesn’t place a high requirement on wireless access rate; wide wireless bandwidth configuration is used
when there are many idle wireless channels and single user places a high requirement on wireless
access rate. Moreover, narrow wireless bandwidth configuration is more effective in sheltered
environment. With advanced rate control algorithm, adapt to channel quality changes quickly while
keeping stable rate as far as possible, so it is very suitable for remote wireless transmission. ACK
overtime automatic adjustment technology detects the distance between access point and client
automatically, adjusts wireless parameters and optimizes the equipment performance.
Before AP enables TDMA, client shall set a priority. When one AP connects multiple clients and
different clients place different requirements on bandwidth, priority shall be set according to bandwidth
requirements of client on present equipment. In case of high bandwidth requirements, it is suggested
that the priority should be set to be high; on the contrary, the priority should be set to be low. Of course, if
all clients place the same requirements on bandwidth, priority of all clients can be the same
TDMA function can be enabled by AP; client can set its own priority. Other manufacturers’ TDMA cannot
intercommunicate with our TDMA.
