'06'LJLWDO0XOWLSRLQW6\VWHP

Design Aspects of Flexible Broadband Fixed Radio Access Systems

'(6,*1$63(&762)
)/(;,%/(%52$'%$1'
),;('5$',2$&&(666<67(06

Document: DMS_T14.doc
Doc. No.: DMS/PMP1/9901
Status: Issue 1.4
Prepared: UC-ON/VTU Dorel Tremurici

DMS_T14.doc 18.01.99 Page 1 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

7DEOHRI&RQWHQWV

 5(48,5(0(1762)02'(51$&&(661(7:25.6 

 *HQHUDO1HWZRUN5HTXLUHPHQWV 

 6SHFLILF5DGLR5HTXLUHPHQWV 

 %$6,&6<67(0'(6&5,37,21 

 0XOWLSOH$FFHVV6FKHPH7UDGHRII 

 %DVLF6\VWHP&RQFHSW 

 7KH)'0$)%$0RGH 

 7KH)'0$'%$0RGH 

 7KH&'0$0RGH 

 5$',26<67(03(5)250$1&( 

 6SHFWUXP(IILFLHQF\ 

 6\VWHP&DSDFLW\ 

 $LULQWHUIDFHVSHFLILFDWLRQV 

 %DVHVWDWLRQVSHFLILFDWLRQV 

 8VHUWHUPLQDOVSHFLILFDWLRQV 

 /LQNUDQJH FHOOUDGLXV DQGDYDLODELOLW\ 

 (QYLURQPHQWDOVSHFLILFDWLRQV 

 0LVFHOODQHRXVVSHFLILFDWLRQV 

 0RGHPDQG5)7HFKQRORJ\ 

 $QWHQQD7HFKQRORJ\DQG6\VWHP/D\RXW 

 3/$11,1*$63(&76 

 &21&/86,216 

DMS_T14.doc 18.01.99 Page 2 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

$EVWUDFW - Design aspects of broadband radio access systems are discussed focus-
ing on new system requirements such as full access network integration, broadband
transmission capacities, high transmission quality and spectrum efficiency as well as
inherent security. The corresponding technical solution shows, that with a careful
system optimisation innovative solutions can be found.

 5(48,5(0(1762)02'(51$&&(661(7:25.6

1.1 General Network Requirements

Within modern upcoming concepts for access networks, the possible physical trans-
mission layers also include radio network solutions. These are not only limited to syn-
chronous or plesiochronous point-to-point (PtP) network elements but can also com-
prise point-to-multipoint (PMP) topologies. In contrast to the more or less static world
of transmission systems, access systems require more flexible and evolutionary solu-
tions, whose features can be summarised as follows:

Ø Evolutionary technical solutions in order to handle existing

and future services in one system concept,
Ø Flexible structures and capacity extension capabilities, sim-
ple integration possibilities in existing and emerging net-
works,
Ø Easy adaptation to different data rates and services, fully
transparent and service independent,
Ø Individual addressing of subscriber bit rates,
Ø Handling of distributive and interactive services,
Ø Standardised and open interfaces with large variety
Ø Optimisation for low configuration, maintenance and service
efforts and cost, high inherent security,
Ø Low cost per traffic channel, fast return of investment.

The proposed access network concept fulfils these requirements. The overall solution
is based on SDH transmission technology as far as possible and offers several physi-
cal transmission layers: copper, coax, fiber and radio. Access and corresponding
trunk networks are monitored and controlled by the same network management sys-
tem.

DMS_T14.doc 18.01.99 Page 3 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

1.2 Specific Radio Requirements

Up to now, FRA (fixed radio access) solutions have been more or less standalone ap-
plications with a variety of mostly proprietary solutions. System designs are either
originating from the well known rural area or derived from mobile communication or
cordless standards (e.g. DECT or GSM fixed radio access). Furthermore, some new
upcoming approaches have been presented featuring higher service qualities than the
conventional solutions and showing the way to a new generation of fixed radio access
systems. The main radio related features of such a new system generation could be
summarised as follows:

Ø Seamless integration into a wireline access network concept,

Ø Compatibility with higher user data rates,
Ø Variable transmission capacity by using software selectable
data rates over a wide range,
Ø Automatic adaptation of RF spectrum to selected data rates,
flexible RF channel allocation, high spectrum efficiency and
high radio cell capacities,
Ø Wide range of microwave frequencies, to cope with various
regulatory situations,
Ø Open interfaces at radio node and subscriber terminal for
multivendor integration,
Ø Bandwidth-on-demand, pay-as-you-go capabilities,
Ø High transmission quality (not worse than within a wireline
network),
Ø ATM compatibility (future extension),
Ø High inherent security, incorporation of encryption and
authentication,
Ø Low overall RF power, to be compatible with possible future
electromagnetic environmental constraints.

DMS_T14.doc 18.01.99 Page 4 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

 %$6,&6<67(0'(6&5,37,21

2.1 Multiple Access Scheme Trade-off

Point-to-multipoint radio access systems - in contrast to point-to-point systems - re-
quire a multiple access method in order to manage the transmission from one central
common base station of a radio cell with a number of terminals at different locations.
From the technical point of view, different methods are available today, using either
an access method in the time domain (TDMA: Time Division Multiple Access), the fre-
quency domain (FDMA: Frequency Division Multiple Access) the code domain
(CDMA: Code Division Multiple Access) and the space domain (SDMA: Space Divi-
sion Multiple Access) or any effective combination thereof.

Any of these methods has advantages and disadvantages, the optimum selection is a
complicated process and depends on a variety of criteria. For the system described in
this paper, after a careful selection process, basically the classical FDMA principle
with some new extension features such as e.g. DBA (Dynamic Bandwidth Allocation)
has been chosen.

FDMA is the most simple and common method to achieve a multiple access to indi-
vidual terminals. Any terminal has its own frequency slot within a common frequency
band. Through the implementation of a software controllable data rate of the individ-
ual terminal a high degree of flexibility can be achieved in comparison to a conven-
tional PtP radio link. With a newly developed technology changing of the transmission
data rate and other modulation parameters "on the fly" i.e. without introducing bit er-
rors has been made possible thus avoiding all the classical drawbacks of conven-
tional FDMA.

Full transparency is established by using FDD (Frequency Domain Duplex) i.e. a

separate frequency band for the forward and return channels is allocated. Although
these new features offer a high degree of flexibility, the basic scheme has some se-
vere disadvantages, especially, if varying traffic is considered.

Conventional FDMA systems even those with variable data rates are bound to fre-
quency slot allocations which have to be oriented to the maximum of the traffic capac-
ity of the corresponding link and are therefore not highly spectrum efficient, if lower
traffic rates are considered. Introduction of DBA capabilities fully avoids these draw-
backs and leads to a more powerful solution in comparison to TDMA and CDMA mul-
tiple access schemes especially in terms of service quality and system capacity.

DMS_T14.doc 18.01.99 Page 5 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

Nevertheless, also considerable progress has been achieved with 2nd generation
CDMA systems currently in development. CDMA through its spreading of the incom-
ing data signal to a wide frequency band offers inherent immunity against interfering
signals. This is of considerable interest in a residential scenario, where only simple
and economic customer terminal solutions with simple installation procedures can be
used. This automatically leads to a wide antenna beam with very poor spatial filtering
capabilities. CDMA and especially W-CDMA (Wide band CDMA) can solve that
problem to a certain extent but at the expense of system capacity, i.e. the number of
users per frequency band is considerably lower than in the FDMA case.

To overcome this dilemma, it has been concluded, to extend the DMS system archi-
tecture by a W-CDMA add-on subsystem which seamlessly can be integrated into the
existing base station layout.

DMS_T14.doc 18.01.99 Page 6 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

2.2 Basic System Concept

New developments concerning radio modem technology lead to an approach, that al-
lows an online bit error free switching of all modulation and demodulation parameters
such as centre frequency and width of the modulation spectrum as a function of data
rates, the amplitude of the modulated carrier and the modulation scheme as well as
the individual channel coding. If this switching can be done dynamically, the solution
offers an unparalleled flexibility:

• Assembly of independent links with individual dynamic configuration

and optimisation
• Complete bi-directional transparency of the transmission channel
• Complete independence of the transmitted service or protocol
• No principal limitation of user bandwidth
• High spectral efficiency through the use of higher order modulation
schemes
• Dynamic trade-off between modulation efficiency and link range pos-
sible
• High system sensitivity through the use of advanced coding schemes
• System capacity principally only limited by the amount of spectrum
available
• Simple coexistence with point-to-point links through FDMA/FDD within
e.g. ITU-R channelisation
• Frequency hopping additionally possible (at the expense of system
capacity)
• Single chip modem solution and digital IF solution leading to low cost
design
• Compatibility with ITU-R and any other special channelisation through
modem flexibility
• Shutdown of single terminal does not affect other links
• Simple RF circuitry at terminal
• Selective encryption on any single link possible

DMS_T14.doc 18.01.99 Page 7 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

* 5DGLR .HUQHO *

1HWZ RUN
,) 5)
02'(0
8QLW
18
02'(0 8QLW 8QLW C
o
m &HQWUDO
5)
,) b 'LVWULEXWLRQ
8QLW 8QLW
i 1RGH

n &'1

e
1HWZ R UN 5)
,)
8QLW 02'(0
8QLW 8QLW
r 02'(0
18

5HP RWH 5DGLR &HQWUDO 5DGLR

6WDWLRQ 556 6WDWLRQ &56

)LJXUH 3ULQFLSOH6\VWHP%ORFN'LDJUDP

Integration into an access network concept can be managed as shown in Figure 1.

Open radio kernel interfaces allow a compatibility with a broad variety of subscriber
and network/switch interfaces using the corresponding multivendor multiplexer or
customer interface equipment.

Various functionalities ranging from simple analog phone up to high data rate applica-
tions are possible without changing the radio principle. The individual links can be
configured according to the special customer needs together with flexible spectrum
allocation algorithms.

According to the individual application, mainly two types of system operational modes
can be chosen, the FBA (Flexible Bandwidth Allocation) or DBA (Dynamic Bandwidth
Allocation) system. Of course, the operational mode can be mixed arbitrarily among
the different terminals.

The W-CDMA subsystem seamlessly integrates into the existing base station equip-
ment and uses the common radio transceiver approach. Therefore, a very interesting
hybrid approach is possible (if the customer owns the corresponding frequency li-
censes) in combining (in the same base station with the same system and manage-
ment software) a high capacity cell for short distances (e.g. the typical city environ-
ment) with a lower capacity cell for longer distances (the typical suburban environ-
ment).

DMS_T14.doc 18.01.99 Page 8 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

2.3 The FDMA/FBA Mode

In the frame of this more simple system configuration, all system parameters are vari-
able on a quasi-static basis, i.e. can be changed by the network management system
on demand or determined by a specified scheduler. This system configuration can be
chosen for higher capacities

$SSOLFDWLRQ 0D[LPXP &XVWRPHU

'DWD5DWH (TXLSPHQW

Large Business 2 Mbps (E1/T1) PABX

(I) or fractional E1/T1 DECT PABX
DECT FRA

Large business up to 8*E1/T1 PABX

(II) or fractional E1/T1 DECT PABX
DECT FRA

LAN st
up to 2 Mbps (1 generation) Bridge
nd
up to 10 Mbps (2 generation)

Multimedia up to 6,3 Mbps (2nd generation) Multimedia

(MPEG II, IV) fwd. and return Settop Box

ATM 10 Mbps (2nd generation) ATM Mux

Leased Line up to 8*E1/T1 -

7DEOH $SSOLFDWLRQVLQ)%$0RGH

DMS_T14.doc 18.01.99 Page 9 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

such as video transmission (with source coding schemes like MPEG II and in future
MPEG IV) as well as with a high amount of locally switched traffic. In the case of the
connection of a second FRA subsystem connected (DECT, GSM or other proprietary
systems) the corresponding link acts as a feeder line. Another interesting application
is given by feeding small base stations of cellular mobile systems by using the same
radio access infrastructure. In principle, the transmission bit rate setting is possible
with a resolution down to 1 Bps, thus being fully future proof, especially for applica-
tions with even enhanced source coding algorithms (MPEG IV).

2.4 The FDMA/DBA Mode

The DBA mode, i.e. the dynamic allocation of spectrum resources within an FDMA
system, is the more complex application and requires additional modem functionali-
ties. In the frame of this operational mode the direct customer radio access for differ-
ent types of services is possible within one common system approach, DBA and FBA
links can be mixed arbitrarily. According to the configuration of the flexible customer
access multiplexer, a variety of service combinations is possible.

Application Data Rate Customer

Equipment
Single POTS 64 kbps Remote Network Unit
Multiple POTS n*64 kbps Remote Network Unit
Single ISDN 64/128 kbps Remote Network Unit
Multiple ISDN n*64 kbps Remote Network Unit
POTS/ISDN up to 30*64 kbps Remote Network Unit
DATA (V11, V35) n*64 kbps Remote Network Unit
POTS/ISDN/DATA up to 2 Mbps Remote Network Unit
Fast Internet (IP) up to 2 Mbps Remote Network Unit

7DEOH $SSOLFDWLRQVLQ'%$0RGH

The DBA mode requires a granularity of 64 kbps and compatibility with common sig-
nalling schemes. To maintain a multivendor environment possibility, the modem/mux
interface is based on G.703 recommendations. Within the radio modem a separate
radio frame is built up transmitting only the used timeslots, at the base station modem
the PCM frame is reinstalled offering the same interface to the base station mux as in
the case of a direct wireline connection.

DMS_T14.doc 18.01.99 Page 10 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

Allocation of frequency resources within the radio link is done by temporarily setting of
a second carrier with the new data and bit error free switching within the modem (mul-
tiplexed modem approach). Switching times are compatible with standard signalling
requirements. This highly dynamic process is monitored by a high speed resource
manager at the radio base station.

All applications are available within the same flexible customer multiplexer which can
be equipped with interface cards according to local requirements.

DMS_T14.doc 18.01.99 Page 11 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

2.5 The CDMA Mode

Referring to fig. 1 CDMA offers the possibility to leave the modem to modem commu-
nication architecture and switch to a modem to multiple modem communication. With
CDMA different users share the same frequency band (the resource for the multiple
access in fact is the available C/I in a single channel). The multiple access is per-
formed by associating individual codes to individual terminals (modems). The actual
approach uses latest technology wide band CDMA where the incoming signal is
spread to a 14 MHz wide spectrum regardless of the data rate. Additionally, the sys-
tem capacity in terms of possible voice channels is enhanced using source coding (32
kBps ADPCM). In the CDMA case the following services are offered.

Application Data Rate Customer

Equipment
Variable data rate 16 – 256 kbps CDMA terminal

Single POTS 32 kbps ADPCM CDMA terminal

Multiple POTS up to 8*32 kbps ADPCM CDMA terminal
Fax/Modem 64 kbps CDMA terminal
Single ISDN 64/128 kbps CDMA terminal
Dual ISDN up to 4*64 kbps CDMA terminal
DATA (V11, V35) up to 4*64 kbps CDMA terminal

Internet up to 256 kbps CDMA terminal

7DEOH $SSOLFDWLRQVLQ&'0$0RGH

The customer terminal unit is different from the FDMA terminal unit offering less flexi-
bility but lower cost, as it specifically designed for the above applications. The radio
specific units are the same as in the FDMA case, nevertheless CDMA allows to utilise
a more compact customer terminal antenna, which is especially useful at lower radio
frequencies. The propagation properties at lower frequencies furthermore offer the
possibility of operating the terminal in a NLOS (near line of sight) mode. It should,
nevertheless, clearly be pointed out, that such an operational mode at frequencies
around 3 GHz can only be achieved at the expense of system capacity and cell size.

DMS_T14.doc 18.01.99 Page 12 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

 5$',26<67(03(5)250$1&(

3.1 Spectrum Efficiency

Spectrum efficiency is a key point in radio transmission, especially if higher link data
rates and high traffic densities are considered. Higher order modulation schemes are
available today enhancing this critical system parameter but at the expense of avail-
able system sensitivity. To achieve a reasonable compromise especially for a low cost
wireless PMP radio solution, different software selectable robust modulation schemes
are available in the FDMA case and can be associated individually and dynamically
to any link allowing an automatic optimisation of link range, transmission quality and
spectrum efficiency at the same time. System capacities may be further enhanced
using cell sectorisation and/or polarisation reuse. A high amount of variable spectrum
filtering allows a sharp spectrum roll-off, additional coding schemes even permit par-
tial spectrum overlap without significant BER deterioration.

It should be noted, that in the W-CDMA mode only QPSK modulation is used.

)LJXUH )'0$6SHFWUXP([DPSOH

VKRZQZLWKRXWVSHFWUXPRYHUODS

DMS_T14.doc 18.01.99 Page 13 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

0RGXODWLRQ &RGH 6SHFWUXP

6FKHPH 5DWH (IILFLHQF\

%LWV+]

QPSK ½ 0.77
QPSK ¾ 1.15
QPSK 7/8 1.35
8-TCM 2/3 1.54
16-TCM ¾ 2.31

7DEOH 6HOHFWDEOH6SHFWUXP(IILFLHQFLHVDQG&RGLQJ

3.2 System Capacity

Overall system capacity is given by the amount of radio spectrum available, the re-
sulting spectrum efficiency, which depends on the distribution of the terminals and the
selected modulation, coding and multiple access scheme as well as the amount of
sectorisation and/or polarisation reuse. In the case of a FDMA/FBA system a corre-
sponding typical example is shown in Table 5.

)UHTXHQF\5DQJH>*+]@   

RF Bandwidth [MHz] 14 30 28
Sectorisation [degrees] 60 45 45

No of E1 per sector 12 27 25
No of E1 per cell (6/8 sectors) 72 216 200
Cell/trunk capacity [Mbps] 147 442 412
Total capacity for all available channels 880 Mbps 2,2 Gbps 7,4 Gbps
in the frequency band [Mbps] @ 26 GHz

Boundary conditions • typical cellular coverage (with interference)

for capacity calculation: • BER < 10-7
• mixture of available modulation schemes

7DEOH 7\SLFDO)'0$)%$6\VWHP&DSDFLW\([DPSOH

/HDVHG/LQHV0RGH )%$0RGH

DMS_T14.doc 18.01.99 Page 14 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
 '06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

In the case of the FDMA/DBA system, any individual link is dynamically adapted to the
local terminal traffic. Therefore, a much higher number of connections than in the
static case can be accomodated. The net capacity of the system then depends on as-
sumptions of the local traffic parameters and the amount of blocking probability speci-
fied. Table 6 shows an example for a contiguous coverage (i.e. with neighboured
cells) and a medium complexity sectorisation arrangement. Table 7 the according
system capacity for Internet traffic.

For CDMA, the net system capacity is primarily given by the amount of C/I available
and the achievable power stability of the RF signal. For lower frequency ranges a
lower degree of sectorisation must be assumed in order to avoid large base station
antenna sizes.

FBA DBA
Mode Mode
Frequency range [GHz] 3,5 10,5 24/26/28 3,5 10,5 24/26
RF Bandwidth [MHz] 14 30 28 14 30 28
Sectorisation° 60 45 45 60 45 45

No. of terminals @ 200 576 536 420 1200 1080

4 lines/CPE
No. of lines in total 800 2304 2144 1680 4800 4320
Cell capacity [Mbps] 51 155 137 51 155 137

No. of terminals @ 45 112 88 108 344 312

30 lines/CPE
No of lines in total 1340 3360 2640 3240 10320 9360
Cell capacity [Mbps] 85 215 170 85 215 170

Boundary conditions • typical cellular coverage (with interference)

for capacity calculation: • BER < 10-7
• for DBA: blocking: < 0.01%
traffic: 0.2 Erl/subscriber

7DEOH 7\SLFDO)'0$'%$6\VWHP&DSDFLW\([DPSOH

6ZLWFKHG6HUYLFHV0RGH )%$DQG'%$0RGH

DMS_T14.doc 18.01.99 Page 15 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

)UHTXHQF\5DQJH>*+]@   

RF Bandwidth [MHz] 14 30 28
Sectorisation 60° 45° 45°

No. of active internet users per sector 900 3240 3000

No. of active internet users per cell 5400 25920 24000

Boundary conditions: • peak rate: 2 Mbps, duty cycle 3%

7DEOH 7\SLFDO)'0$'%$,QWHUQHW7UDIILF&DSDFLW\([DPSOH

6ZLWFKHG,QWHUQHW6HUYLFHV0RGH '%$0RGH

It should be mentioned, that the a.m. examples only show typical cases. For a de-
tailed computation of individual scenarios special tools are available to evaluate cus-
tomer specific solutions.

DMS_T14.doc 18.01.99 Page 16 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
 '06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

3.3 Air interface specifications

)UHTXHQF\EDQG>*+]@ ± ± ± ±

Multiple access scheme FDMA W-CDMA FDMA FDMA

Air interface protocol FBA and DBA dynamic FBA and DBA FBA and
DBA
Modulation schemes QPSK QPSK QPSK QPSK
(software configurable)
8-TCM 8-TCM 8-TCM
16-TCM 16-TCM 16-TCM
Channel coding convolu- convolu- convolu- convolu-
(software configurable) tional tional tional tional
Trellis Trellis Trellis
Reed Reed Reed
solomon solomon solomon
Demodulation Coherent Coherent Coherent Coherent
Viterbi Viterbi Viterbi Viterbi
decoder decoder decoder decoder
Channel bandwidth [MHz] 14 14 30/28 28
Channel allocation duplex duplex duplex duplex
Standards compliance ETSI DEN/TM ETSI DEN/TM ETSI DEN/TM ETSI DEN/TM
04040, 04040, 04040, 04040,
CEPT REC T/R CEPT REC T/R CEPT REC T/R CEPT REC
T/R
14-03 E 14-03 E 12-05 E
13-02 E
other frequency bands upon request

7DEOH $LU,QWHUIDFH6SHFLILFDWLRQV

DMS_T14.doc 18.01.99 Page 17 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
 '06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

3.4 Base station specifications

)UHTXHQF\EDQG>*+]@ ±  ±

Architecture modular, scaleable, freqency independent indoor units,

freqency dependent outdoor units
Antenna sectorisation 60° 15° 15°
45° 45°
90° 90°
No of sectors per cell 1-6 1 - 8 (24) 1 - 8 (24)
Antenna type planar, sector beam, low sidelobes, low cross polarisation

Interconnection single coax

indoor/outdoor
Network interfaces STM-1, STM-4, 34 Mbps, 2 Mbps, QD2, Q3
Network protocols CAS, V5.1, V5.2, VB5

7DEOH %DVH6WDWLRQ6SHFLILFDWLRQV

DMS_T14.doc 18.01.99 Page 18 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
 '06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

3.5 User terminal specifications

)UHTXHQF\EDQG>*+]@ ± ± 

Architecture modular, scaleable, frequency independent indoor units, fre-

quency dependent outdoor units
Interconnection indoor outdoor single coax
Antennas planar, high gain, planar, high gain, planar, high gain,
low sidelobes, low sidelobes, low sidelobes,
low cross- low cross- low cross-
polarisation polarisation polarisation
30 cm parabolic
60 cm parabolic
User interfaces n*POTS, n*ISDN (Uo, So), V.35, V.11, n*64 kbps, 10BaseT,
(depending on network unit) E1, fractional E1, n*E1(n up to 8), T1,
Local PC element manager

7DEOH 8VHU7HUPLQDO6SHFLILFDWLRQV

DMS_T14.doc 18.01.99 Page 19 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
 '06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

3.6 Link range (cell radius) and availability

)UHTXHQF\EDQG>*+]@ ± ± 

Rainzone up to E up to 15 km (*) up to 10 km 3 - 5 km
Data rate 2 Mbps
BER < 10-6
Non availability 99,995 %
Rainzone up to K up to 15 km (*) up to 10 km 3 - 5 km
Data rate 2 Mbps
BER < 10-6
Non availability 99,99 %
Rainzone up to P up to 15 km (*) up to 5 km 1 - 3 km
Data rate 2 Mbps
-6
BER < 10
Non availability 99,95 %

Remarks: typical average valuesfor standard system(*) range limited by interference

configuration, enhanced link ranges with special system configurations

7DEOH /LQNUDQJH FHOOUDGLXV DQGDYDLODELOLW\

DMS_T14.doc 18.01.99 Page 20 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
 '06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

3.7 Environmental specifications

)UHTXHQF\EDQG>*+]@ ± ± 

Temperature range Indoor units: ETS 300 019, class 3.1, 4.1
Outdoor units: ETS 300 019, class 3.1, 4.1
Power consumption Terminal: depending on configuration
Base station: depending on configuration
Physical dimensions Terminal: outdoor 3,5 GHz: 341×316×100
w x h x d [mm] units: 10,5 GHz: 275×460×60
26 GHz: 212×389×83
indoor RNU30 : 435×305×249
units: RNU8: 268×305×249
RNU2M: 19“ rack mount 1 HU
RNU2MxN: 19“ rack mount 7 HU

Base station: outdoor 3,5 GHz: 477×340×100

units: 10,5 GHz: 275×460×110
26 GHz: 212×389×94
indoor 19“ rack mount
units: acc. to system capacity
Wind loading Operation: 164 km/h
Survival: 250 km/h
Electromagnetic com- ETS 300 385, EN 50081-1, EN 50082-1, DIN VDE 0878,
patibility and safety Part1/3, EN 60950

7DEOH (QYLURQPHQWDO6SHFLILFDWLRQV

DMS_T14.doc 18.01.99 Page 21 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
 '06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

3.8 Miscellaneous specifications

)UHTXHQF\EDQG>*+]@ ± ± ±

Security, Standard: Identification of individual subscriber

Fraud prevention by the network management system
Optional: SIM card reader and software controlled
per link authentication
Optional: Encryption subsystem (software enabled)
DES standard
Alignment tool Installation and alignment kit
Planning tools Planning tools for business and cell/link planning upon
request

7DEOH 0LVFHOODQHRXV6SHFLILFDWLRQV

DMS_T14.doc 18.01.99 Page 22 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

3.9 Modem and RF Technology

Modulation and channel coding are the key technologies in radio systems for band-
width efficient transmission of digital information. The DMS system kernel consists of
a variable data rate fully digital modem. Modulation is based on well known and ro-
bust phase shift keying techniques. Advanced channel coding techniques like con-
volutional coding and Viterbi decoding as well as even more powerful Trellis coding
and optionally concatenated Reed-Solomon block coding are applied to guarantee for
most efficient use of bandwidth and offering a good service quality, i.e. low bit error
rates at the same time.

Due to the sophisticated modem approach, very high system sensitivities can be
achieved. This compensates to a certain extent the lower system gain in comparison
to a point-to-point connection with high gain antennas on both sides of the link. Ta-
ble 14 demonstrates these possibilities by comparing modulation sensitivities and
spectrum efficiencies for different system options. Concerning the spatial distribution
of terminals, higher order schemes with better spectrum efficiency can be used for
terminals near to the central station, whereas for more distant terminals the optimum
sensitivity scheme can be chosen.

Modulation Eb/No [dB] Coding

Scheme BER<10-7 (RS: Reed Solomon)
QPSK (3/4) 4,5 Convolutional, RS
8TCM (2/3) 5,4 Convolutional, Trellis, RS
QPSK (3/4) 6,5 Convolutional
8TCM (2/3) 7,6 Convolutional, Trellis
16TCM(2/3) 11,2 Convolutional, Trellis

7DEOH 0RGHP3HUIRUPDQFH

The system concept is based on a completely independent modem and radio function.
This allows a flexible adaptation to existing and future special regulatory issues for
microwave PMP access radios. Due to the extremely flexible spectrum arrangement
facilities, any adaptation to future channel arrangements is easily possible. Never-
theless, also an application within existing ITU-R regulations (e.g. sub-bands with
n×3.5 MHz channel spacing) may be envisaged. Due to the advanced modem sensi-
tivity, RF power levels at terminal and radio node station can be held within reason-
able limits. The RF device normally is integrated with the antenna and only provides
the frequency conversion. Most of the IF processing is implemented in digital technol-

DMS_T14.doc 18.01.99 Page 23 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

ogy. According to the different possible frequency ranges, the transceiver architecture
has been chosen to be compatible with different frequency duplex situations. RF con-
version units and antennas are integrated into a compact outdoor unit, according to
the frequency band different RF technologies such as planar micro strip technology
and/or MMIC are used. The outdoor unit is connected to the indoor unit (s) via a low
cost single coax cable.

Parameter Specification
Frequency ranges Acc. to ITU-R
or special bands
Channelisation e.g n*3,5 MHz
or special channelisation

RF power (terminal) 10-20 [dBm]

RF power (radio node) 20-30 (35) [dBm]
Receiver noise figure 3 – 8 [dB]
Typical link ranges 3-15 [km]
ATPC (inbound) inherent system feature
ATPC (outbound) inherent system feature

7DEOH 5)3HUIRUPDQFH

Frequency Specification/ Link

Band [GHz] Recommendation Range [km]
Normal Conditions
3,400 – 3,600 CEPT/ETSI up to 15
10,150 – 10,650 ETSI up to 10
24,500 – 26,500 ITU-R up to 3
27,500 – 29,500 FCC below 3

7DEOH 5))UHTXHQF\%DQGV

DMS_T14.doc 18.01.99 Page 24 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

3.10 Antenna Technology and System Layout

)LJXUH 7HUPLQDO2XWGRRU8QLW

DMS_T14.doc 18.01.99 Page 25 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

)LJXUH &XVWRPHU,QGRRU8QLW 518

)LJXUH 7HUPLQDO5DGLDWLRQ3DWWHUQ

DMS_T14.doc 18.01.99 Page 26 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

Within the frame of a PMP radio solution in the access range, link performance and
the corresponding antenna solutions together with appropriate planning tools play an
important role. Traffic capacity within the radio cell and link transmission quality can
considerably be influenced by enhanced antenna concepts and careful planning.
Therefore, special antenna concepts have been developed in terms of high system
flexibility and compatibility with esthetical requirements.

)LJXUH 6HFWRUHG%DVH6WDWLRQ2XWGRRU8QLW

)LJXUH 6HFWRUHG%DVH6WDWLRQ5DGLDWLRQ3DWWHUQ

DMS_T14.doc 18.01.99 Page 27 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

The system principle is based on an omnidirectional or sectored radiation pattern

concerning the radio base station with a prescribed low sidelobe elevation pattern, the
terminal is connected to a high gain antenna (integrated with the RF unit) also with
low sidelobe pattern requirements in order to minimise the influence of disturbing
rays. All these concepts (except the simple omnidirectional type) are suited for dual
polarisation operation. Together with moderate system bandwidths, planar types of
antennas are a very feasible and economic solutions especially concerning system
modularity and optical outfit.

The current line of antennas available is based on a micro strip solution, that can be
easily adapted to different customer requirements both for a high gain directional so-
lution and for a modular sectored arrangement with different sectorisation angles. Al-
though an omni-directional cell is the most simple case and in many applications ful-
fils system capacity requirements, the use of sectorisation will be more favourable in
terms of propagation issues, optimum coverage capabilities and available system
gain. Thus, different granularities of sectorisation are available down to 15° at pres-
ent. Due to a very high roll-off of the radiation pattern considerable reuse capabilities
can be expected because the overlap region between adjacent sectors can be held
small.

Passive combination of sectored antennas are possible but lead to a very high deg-
radation of system gain due to the considerable power division attenuation. Therefore,
an active principle is used combining each sectored antenna with an integrated trans-
ceiver. This leads to a very high system flexibility, because different sectorisation
schemes can be combined in a single cell according to the spatial distribution of the
user terminals.

At higher microwave frequencies the available link ranges reduce considerably due to
the increased rainfall rates. Therefore, in these frequency ranges, special arrange-
ments with parabolic or lens horn antennas are available to increase the distance in
special cases. The microwave radio units therefore are equipped with standard
waveguide interfaces.

DMS_T14.doc 18.01.99 Page 28 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

 3/$11,1*$63(&76

Despite a necessary high spectrum efficiency new broadband high capacity radio ac-
cess systems nevertheless require a considerable amount of spectrum resource
which is not available a lower frequencies. Therefore, for normal environments, LOS
(Line of Sight) propagation conditions are required as it is well known from conven-
tional point-to-point radio link systems. Corresponding system planning tools addi-
tionally have to support specific urban propagation constraints (e.g. multiple reflec-
tions and scattering) and cellular environments. Although in many cases a clear LOS
situation within an urban area does not require a high planning effort, careful planning
of the base station location is of high interest to get as many useable terminal loca-
tions as possible.

Conventional tools are normally not suited for this application because they are based
on coarse terrain data bases and incorporate no specific urban elements (e.g. build-
ings) and use statistic propagation models. Therefore, a new class of planning tools
had to be developed in parallel allowing a high quality link planning within urban sce-
narios by using terrain and building data bases with high spatial resolution and incor-
porating deterministic propagation models. Besides the standard output such as link
range and availability as a function of the modulation and coding scheme selected
and the weather conditions applied the propagation model also incorporates possible
multiple reflection and diffraction capabilities. AOA (angle of arrival) of disturbing rays
can be computed as well as the PDP (power delay profile) function in order to evalu-
ate the time dependent behaviour of any required link.

The Base Station and Terminal planning steps are:

• LOS (line of sight) analysis

• Determination of maximum cell radius
• Sectorisation
• Interference analysis
• Traffic analysis

Typical results of the optional BOSCH Telecom DMS planning tool CALIPH+ are
shown with the following figures.

DMS_T14.doc 18.01.99 Page 29 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

)LJXUH 7\SLFDO8VHU,QWHUIDFHRIWKHRSWLRQDO&$/,3+3ODQQLQJ7RRO

;:LQGRZV26)0RWLI25$&/('DWDEDVHRQD+38;

:RUNVWDWLRQRSHUDWHGE\+38;9HUVLRQ

DMS_T14.doc 18.01.99 Page 30 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

)LJXUH 7\SLFDO&$/,3+'LJLWDO0DS9LHZHU

DMS_T14.doc 18.01.99 Page 31 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

)LJXUH 7\SLFDO6HFWRUHG%DVH6WDWLRQ/26$QDO\VLV &$/,3+

WKLVWRROLVRSWLRQDODYDLODEOHWRWKHFXVWRPHURQGHPDQG

DMS_T14.doc 18.01.99 Page 32 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.
'06'LJLWDO0XOWLSRLQW6\VWHP
Design Aspects of Flexible Broadband Fixed Radio Access Systems

 &21&/86,216

A next generation of fixed radio access point-to-multipoint systems has been pre-
sented offering new and enhanced features such as FDMA/DBA and advanced mi-
crowave and antenna technologies. The seamless integration of these new radio
technologies into modern access network concepts leads to extremely flexible solu-
tions for almost any service scenario.

This integral system approach is superior to proprietary standalone and application

specific fixed radio access solutions especially concerning operability and mainte-
nance via a common network management approach. A local mobility feature may be
added by combining the system e.g. with a DECT subsystem.

As long as fixed radio access systems are considered, no compromise concerning the
transmission quality and security in comparison to a wireline network can be ac-
cepted.

These features together with high system capacities and spectrum efficiencies are
possible using advanced modulation and coding concepts. Limited spectrum avail-
ability in the future can be overcome by additionally using even more enhanced
source coding schemes than today. These possibilities ensure the competitiveness of
radio technologies also for the future.

DMS_T14.doc 18.01.99 Page 33 of 33

© BOSCH TELECOM GmbH besitzt alle Rechte auch für den Fall von Schutzrechtsanmeldungen. Jede Verfügungsbefugnis, wie Kopier- und Weitergaberecht, bei uns
© This document is the exclusive property of BOSCH TELECOM GmbH, also in case of patents . Without their consent it may not be reproduced or given to third parties.