User's Manual

12 P330 Data Sheet / User Guide
DRAFT
The RangeNet API allows the user to define a network and to define the behavior of the radios in the
system. Operation of the network is controlled by the P330. In particular, the P330 is responsible for
scheduling range requests, maintaining all of the neighbors in a database, and passing data between
the Host and the network. The Host computer function is thereby limited to monitoring and
supervision, thus significantly offloading its responsibilities.
The RangeNet API provides the user with tools to define and monitor the network. For example:
 The network can be defined using two different time-sharing protocols: ALOHA
(randomized) or TDMA (Time Division Multiple Access).
 If the ALOHA protocol is used, then the average interval and the random variation of that
interval can both be defined. The average interval can be manually or automatically throttled
based on the number of units in the system. Radio behavior can be limited on a per unit basis
such that some units initiate and respond to range requests, while others initiate-only or
respond-only. In addition, some units can be instructed to limit their interactions to a subset
of the network members. While most ALOHA networks have an efficiency of 19%, the
efficiency of this ALOHA network is approximately 38%, making it equivalent to the
performance of a Slotted ALOHA system.
 If the TDMA protocol is used, then the user can define a slot map that provides each radio
with instructions on when and to whom and with what parameters it should communicate.
 Because the P330 supports multiple communications channels, it is possible to operate either
the ALOHA or TDMA protocol with a CDMA overlay.
 Because the P330 network schedules range requests, it avoids the overhead of Host to P330
communications and can therefore run at a higher ranging rate.
 The P330 network maintains a neighbor database. Besides noting all of the members of the
network and their ranges, this database also contains a large body of statistics and other
useful information. For example, the database includes received signal strength, approach
velocity, effective ranging rate, and signal quality.
The RangeNet API also provides the user with the ability to enable the P330s to compute their
location based on ranges generated by the network. This capability does not limit the user’s ability to
independently construct a Host based localizer.
 The P330 API supports three localization modes: IDLE (awaiting instructions), Autosurvey
(anchors use UWB ranging to self locate) and Tracking (P330s compute position in the
system and report)
 The API allows the Host to connect to any unit and use that connection to report the location
of any unit in the system as well as all of the range measurements taken in the system.
 Based on instructions from the user, the P330 will compute either X and Y locations or X, Y
and Z locations, variance and covariance information and report those values through the
API.
While these are all powerful network tools, the complexity inherent in this richness can make it
difficult to visualize operation through just the API. The RangeNet GUI fills this gap. Not only does
the RangeNet GUI allow the user to configure the system, but it also provides a means for easily
maintaining different configurations, monitoring results, evaluating the performance of individual
links in the network, monitoring the neighbor database, reporting location information and quality
statistics from all units in the system. For example, the RangeNet GUI allows the user to:
 Define all types of configuration information (including TDMA slot map, ranging