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Z500a
16 June 2004
Furthermore, The Z500a is multislot class 10 meaning up
to four time slots can be used for downlink data and up to
two timeslots can be used for uplink data. This
configuration is commonly referred to as 4+2 with a
maximum sum of 5. With EDGE, it is possible to achieve
a data rate of up to 59.2 kbit/second per time slot when
Modulation and Coding Scheme 9 (MCS-9) is used so
the Z500a can achieve rates of up to 236.8 kbit/second in
the downlink direction and up to 118.4 kbit/second in the
uplink direction. These rates are subject to radio
conditions.
Data rates per time slot for all of the EDGE coding
schemes are given in the following table.
In GMSK and 8-PSK the input bit sequence is
represented by a phase shift of the RF signal. For GMSK,
a phase shift occurs for each input bit. For 8-PSK, a
sequence of three input bits represents a symbol and
leads to the corresponding phase shift. In other words,
each input symbol in 8-PSK causes a phase shift to one
of eight defined states. This is illustrated in the following
figure.
To minimize amplitude modulation, the 8-PSK scheme
illustrated in the previous figure is offset by an angle of
3π/8 in EDGE. This prevents the amplitude from
crossing the origin in the IQ plane. The 8-PSK states
with the 3π/8 offset are shown in the following figure.
The data rates provided by EDGE open up new
possibilities in multimedia, mobile internet access, and
basic data services. EDGE provides the next logical step
in the development of mobile networks.
Connection via cable
The Z500a supports data connectivity through its system
connector. USB and RS-232 connection protocols are
supported through available data cable accessories. For
GPRS or EDGE data sessions, maximum throughput is
made possible with the Z500a providing the air interface
for your connected mobile computer.
USB
Employing the user-friendly USB standard, the DCU-11
cable accessory is an easy way to connect your Z500a
and PC or PDA. The USB cable is ideal for
synchronization or surfing the Internet on a mobile
computer through your Z500a phone with improved
transmission speeds than previous phone models.
Necessary drivers are found on the CD included with the
accessory cable.
Coding
Scheme
Modulation Transmission
Rate/Time Slot
(kbit/second)
MCS-1 GMSK 8.8
MCS-2 GMSK 11.2
MCS-3 GMSK 14.8
MCS-4 GMSK 17.6
MCS-5 8-PSK 22.4
MCS-6 8-PSK 29.6
MCS-7 8-PSK 44.8
MCS-8 8-PSK 54.4
MCS-9 8-PSK 59.2
In GMSK modulation, each input bit
causes a phase shift of ± 90 degrees to
the RF vector in the IQ plane.
In 8-PSK, each symbol represents
three input bits and causes a phase
shift of the RF vector to one of eight
defined states in the IQ plane.
Q
I
111
011
010
000
001 101
100
110