XBee®/XBee‐PRO® ZB SMT RF Modules
•Broadcast transmissions can support 8 bytes more than unicast transmissions.
•If source routing is used, the 16-bit addresses in the source route are inserted into the RF payload space. For
example, if NP returns 84 bytes, and a source route must traverse 3 intermediate hops (3 16-bit addresses),
the total number of bytes that can be sent in one RF packet is 78.
•Enabling APS encryption (API tx option bit set) will reduce the number of payload bytes by 4.
Throughput
Throughput in a ZigBee network can vary by a number of variables, including: number of hops, encryption enabled/
disabled, sleeping end devices, failures/route discoveries. Our empirical testing showed the following throughput
performance in a robust operating environment (low interference).
Data Throughput*
Configuration
Data Throughput
1 hop, RR, SD
58kbps
1 hop, RR, SE
1 hop, RE, SD
1 hop, RE, SE
1 hop, ER, SD
1 hop, ER, SE
4 hops, RR, SD
4 hops, RR, SE
34kbps
Not yet available
Not yet available
Not yet available
Not yet available
Not yet available
Not yet available
RR = router to router,
RE = router to end device (non-sleeping),
ER = end device (non-sleeping) to router,
SD = security disabled,
SE = security enabled.
4 hops = 5 nodes total, 3 intermediate router nodes
* Data throughput measurements were made setting the serial interface rate to 115200 bps, and measuring the
time to send 100,000 bytes from source to destination. During the test, no route discoveries or failures occurred.
ZDO Transmissions
ZigBee defines a ZigBee Device Objects layer (ZDO) that can provide device and service discovery and network
management capabilities. This layer is described below.
© 2010 Digi International, Inc.
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DCD [ DIGITAL CORE DESIGN ]
