Page 231 - GuideFWA

L(d ) = 38 + 30log d d < 20 m

L(d ) = -1 + 60log d 20 m = d < 40 m

L(d ) = -97 + 120log d d = 40 m

where d is the distance in meters between the PWT base and handset and L(d ) is the median

path loss is dB. For this model, shadow fading is assumed to be lognormal withs = 8dB . For

90th percentile coverage, a shadow fade margin of 1.29s ? 10 dB must be included in the link
budget. The maximum median path loss therefore is:

( )Lmax = PTX + Gbase + Ghandset - -115 + N FWA + 25 - 10 ,

where PTX is the PWT transmit power (assumed 19.6 dBm), Gbase is the PWT base antenna gain
(assumed 3 dBi), and Ghandset is the PWT handset antenna gain (assumed 0 dBi). The effective
cell radius is then computed from the Ericsson path loss formula above.

5.2. AENS VIEW

The above LMNQ text, submitted in the X meeting of PCC.III in Natal, is a re-edition of
document PCC.III/919/97 [17] which was already submitted in the IX meeting of PCC.III in
Mexico, and it contains exactly the same information.

Even when in Mexico, the experts group already discussed partly the document [17], and some
useful comments were provided to Lucent about this report, none of those comments have been
included in this new edition and then, the paper still contains the same errors that those indicated
in Mexico.

These errors are mainly related to the input parameters and assumptions used for calculations:

• The above text [16], it is assumed a traffic of 300 Erlangs/Km2, and an area around the UPCS
receiver of 5km of radio (d=5km), where FWA transmitters can be located randomly. This is
an unrealistic scenario:
- Such traffic density, though effectively indicated in ETSI ETR 310 as mentioned in
[16], is related to the TOTAL FORESEEN TRAFFIC INCLUDING FUTURE DATA
SERVICES FOR ALL THE RLL (FWA) SYSTEMS, but not for an unique DECT
system!!.
- Moreover, if we assume this managed traffic in such area (d=5km means about 78.5
km2), we will have a total of near to 300000 FWA subscribers (with an average of 80
mE/subscriber) in a circle of 5 Km2 !!!. Where is it foreseen such so optimistic
scenario for a single DECT operator ?!!.
Obviously, this is a misunderstanding of the ETSI ETR 310 document. The current FWA
world-wide contracts are based on traffic about 30 Erl/Km2 in wide urban areas. Sometimes,
obviously, higher traffics can be considered, but never in such large area.

• In [16], it is assumed a micro-base station DECT deployment with omnidirectional antennas
in high urban scenario. This is, again, an error: in this kind of scenarios (and, in general, in

Inter-American Telecommunication Commission 217