Other Satellite Navigation Systems - Understanding GPS: Principles and Applications - page 621

Essentially, the benchmarks are a special class of user sets deployed in a network at
fixed sites with known presurveyed geodetic locations across China [43, 44].

11.2.7.5 BNTS Fleet Management Centers
The BNTS is designed to allow civil fleet managers to monitor, determine locations
of, and communicate with mobile users of the system. Currently, there are two net-
works, one for military users and a second for civil users. BDstar is developing the
military fleet management service under a contract signed in April 2002.
ChinaTopComm is developing a civil service as part of a joint venture initiated in
December 2001. Company literature indicates that BDstar may also enter the civil
fleet management market at a later date. Each company plans to provide two levels
of service for military and civil users: one targeted for high-volume fleet managers
and a second targeted for low-volume fleet managers. The main difference between
the two levels of service is the complexity of the fleet management center and the
communication links used to connect the fleet manager with the POC [43, 44].

• Low-volume service architecture. Both BDstar and ChinaTopComm are also
developing similar low-capacity fleet management services using the BeiDou
system to communicate between the POC and the individual fleet manage-
ment centers [43, 44].

High-volume service architecture. Both BDstar and ChinaTopComm are
developing similar high-capacity fleet-management services. The high-volume
service uses traditional communications links (like very small aperture termi-
nals, terrestrial, microwave, fiber-optic, and landline) to establish wide-area
computer network connectivity between the POC and the individual fleet
management centers. The Chinese have provided limited details on the design
and capability of a fleet management center. The high-volume center consists
of several map displays and communications consoles [43, 44].

•

11.2.8 RDSS Navigation Services
The Chinese plan five basic positioning and communication services using the
BeiDou RDSS capability. The Chinese service providers indicate that these services
are currently operational. These are [43, 44]:

RDSS positioning of mobile users for navigation and fleet management. The
BNTS provides about 20-100-m two-dimensional accuracy in areas where
the system is calibrated with benchmarks in a transmit and receive mode.
Because the positions are calculated at the POC, the system can also be used
for fleet management [43, 44].

•

Broadcast of accuracy corrections and integrity information for use with the
GPS and GLONASS systems . The BNTS RDSS also provides accuracy correc-
tions for and information on the integrity of U.S. GPS and Russian GLONASS
so that the Chinese military and civil users can use these systems more reliably.
In this mode of operation, the users need only to passively receive the BNTS
(S-band) and GPS (L-band), or GLONASS (L-band) signals [43, 44].

•