9XTend™
OEM
RF
Module
–
Product
Manual
v1.2.4
©
2005
MaxStream,
Inc.
Confidential
&
Proprietary
38
4.2.
Streaming Mode
Attributes:
Highest
data
throughput
Lowest latency and jitter
Reduced
immunity
to
interference
Streaming mode transmissions never acknowledged by receiving module(s)
Required Parameter Values (TX Module):
RR (Retries) = 0
Related Commands:
Networking (DT, MK, MY), Serial Interfacing (PK, RB, RO, TT)
Recommended Use:
Mode is most appropriate for data that is more sensitive to latency and/or
jitter than it is to occasional packet loss. For example: streaming audio or video.
4.2.1.
Streaming Mode Connection Sequence
Figure
4.3.
Streaming
Mode
State
Diagram
When streaming data,
RB and RO parameters
are used only on the
first packet. After
transmission begins,
the TX event will
continue uninterrupted
until the DI buffer is
empty or the streaming
limit (TT Command) is
reached. As with the
first packet, the p
of each subseque
packet includes up t
the maximum pack
size (PK Command).
The streaming lim
ayload
nt
o
et
it is
specified by the
transmitting module as the maximum number of bytes the transmitting module can send in one
transmission event. If the TT parameter is reached, the transmitting module will force a random
delay of 1 to RN delay slots (exactly 1 delay slot if RN=0).
Subsequent packets are sent without an RF initializer since receiving modules stay synchronized
with the transmitting module for the duration of the transmission event (from preceding packet
information). However, due to interference, some receiving modules may lose data (and
synchronization to the transmitting module), particularly during long transmission events.
Once the transmitting module has sent all pending data or has reached the TT limit, the
transmission event ends. The transmitting module will not transmit again for exactly RN delay
slots if the local (i.e. transmitting module’s) RN parameter is set to a non-zero value. The
receiving module(s) will not transmit for a random number of delay slots between 0 and (RN-1) if
the local (i.e. receiving module’s) RN parameter is set to a non-zero value. These delays are
intended to lessen congestion following long bursts of packets from a single transmitting module,
during which several receiving modules may have become ready to transmit.
Events through the
“Transmit Packet” process
are common to all RF
communication options.
Refer to the Transmit Mode
section [p11] for more
information.
