antennas, MHAs and feeder networks to be installed. In many networks sites will also be shared by at least two operators. Co-siting The term ‘co-locating’ shall be used when BSs are installed at the same site. When sites are co-located and share feeders and antennas this shall be called ‘co- siting’. Basically the same isolation requirements are still vali d as in co-located sites but the means to achieve this could be different. Different kinds of sharing situations may be distinguished, such as antenna and/or feeder sharing, or there could even be multi-mode BSs that share the same cabinets, site support equipment, transmission, feeders and antennas. In the basic situation, there would be an existing BS with the required site support equipment, feeders and antennas, and the operator installs a WCDMA BS on the same site. If the existing system is GSM1800, the attenuation of the feeder would be of the same order as in WCDMA, but in the case of GSM900 the attenuation of the feeder should be checked and changed if needed. Single-mode antennas can be replaced by multi-mode antennas. One example is shown in Figure 5.13. Based upon the preceding discussion and the assumed NFs in Section 5.1.4, the isolation between a WCDMA BS cab inet and a GSM900 BS cabinet should be at least 40 dB whereas the isolation between a WCDMA BS cabinet and a GSM1800 BS cab inet should be at least 45 dB. If the receiver NF is greater than that assumed – e.g., for an active distributed antenna system indoor solution – then the isolation requirement can be reduced. WCDMA–GSM Co-planning Issues 297 WCDMA BS GSM BTS Diplexer Iub Iub/Abis To/From RNC/BSC Diplexer Figure 5.13 Example of site, feeder and antenna sharing. The way in which this isolation requirement is achieved depends upon the detai led site design. If a diplexer is being used to combine the WCDMA and GSM signals such that they can share the same feeders then the diplexor provides the majority of the isolation requirement. A diplexer typically offers 40 dB of isolation between the GSM and W CDMA systems. By changing the single-mode BS to dual- or triple-mode, the space required could be smaller due to the single-site support package. 5.3.1.3 Antenna Configurations Interference between other systems and the WCDMA band depends heavily on the antenna configurations used for both systems. The main problem has been identified with the GSM1800 band; all other systems pose little or no risk of blocking and/or intermodulation with the WCDMA band. Therefore, only the GSM1800 case is further investigated. If antennas for both GSM and UMTS systems have to be mounted on a single carrier pole, the usual 120  three-sector configuration with vertical stacking of GSM and UMTS antennas seems to be a suitable solution, providing isolation values of approximately 30 dB between sectors and systems. If diversity reception is needed, the diversity branches of both systems can be handled by a single physical antenna (assuming dual-band antennas). This is beneficial when the diversity antenna is as far as possible from the (possibly interfering) GSM transmit antenna. Such a triple-stack antenna requires tall poles and may not be feasible in many locations (Figure 5.14). On large flat roofs, isolation between antenna positions can be improved by setting GSM and UMTS antennas physically apart, so that no direct Line-of-Sight (LOS) connection between them exists. One way to do this is by lowering one set of 298 Radio Network Planning and Optimisation for UMTS 120 deg front view top view > 2m > 2m GSM TX/RX UMTS TX/RX GSM & UMTS RX div. Figure 5.14 Possible antenna configuration for dual-system GSM and UMTS site (with diversity). antennas down over the edge of the rooftop, if that position is available and suitable from a radio propagation perspective. 5.3.1.4 Traffic and Service Distribution between Systems Traffic between systems could be separated according to the type of service – e.g., voice and low-speed data traffic could be directed mainly into the 2G network, whereas higher speed data traffic can be directed into the WCDMA. Traffic sharing between layers can be implemented so that the high-speed data traffic is concentrated in pico- and micro-cells and the low-speed data and voice traffic in macro-cells. This is reasonable, because in WCDMA the coverage is tightly bound to the data speeds through processing gain, the higher data rate implying smaller coverage. The services can be handed over as a function of the loading – e.g., speech services can be handed over from WCDMA to 2G if loading is higher than 10 % – which in practice directs speech services into the 2G network. Subscribers could be classified into different groups that have different rights depending on their subscription, and accordingly redirected to the relevant systems. Subscribers with lower priority could be redirected to the 2G network, which has lower maximum data rates for different services. Packet data users who might suffer from excessive delays could be handed over to whichever network has the most extra capacity available. 5.3.1.5 Coverage and Capacity At the beginning of WCDMA deployment, coverage will not be continuous, but it could be extended by selective handover to the 2G network. In areas where WCDMA coverage is continuous, dual-mode or multi-mode mobiles could be set to start their calls in the WCDMA network by proper setting of idle mode parameters. By doing this, the loading between 2G and WCDMA networks can be balanced and in some cases reduce the traffic in overloaded 2G networks: see Figure 5.15. WCDMA–GSM Co-planning Issues 299 WCDMA WCDMA WCDMA WCDMA WCDMA WCDMA GSM GSM GSM GSM GSM GSM GSM GSM GSM GSM GSM GSM Handover WCDMA → GSM for coverage extension Handover GSM → WCDMA for capacity extension or service optimization Urban area Rural area Handover GSM !WCDMA for capacity extension or service optimisation Figure 5.15 Schematic view of handovers between GSM and WCDMA networks for load and coverage reasons. Such handover for coverage reasons should be initiated sufficiently early, because during compressed mode measurements higher power is needed if spreading factor splitting is used. If the mobile is located at the cell edge and is already transmitting with full power, it cannot increase its transmit power further and the connection might be lost if handover is not started early enough. To avoid this kind of problem, handover statistics can be used to determine the sites where inter-system handovers happen most frequently and trigger compressed mode measurements early enough. Instead of switching to compressed mode, blind handover ca n be performed if both systems are located at the same site, since path loss remains the same. Blind handover is especially useful for Non-Real Time (NRT) users, as synchronisation for Real Time (RT) users might take too long, leading to deterioration of connection quality below acceptable limits. Load sharing between 2G and WCDMA networks can be exploited to make full use of their capacity and to achieve some trunking gain, as their resources are in the same pool (see Table 5.7). It is seen that the trunking gain increases as the used data rate increases. Load sharing operation is closely related to how traffic and services are distributed between systems. Speech users can be kept in the 2G network as long as the loading of that network is below the pre-defined threshold, whereas high-speed data users can always be handed ov er to the 3G network if it is available. The order of the mobiles that are handed over to the other radio system can be determined according to their service, transmit power and type of connection. 5.3.1.6 Joint Optimisation Resources in 2G and WCDMA networks can be fully utilised if their management and deployment can be jointly optimised. In order to effe ct successful joint optimisation, there should be a means of gathering performance data from the active network, analyse it and change the parameters accordingly. Handover parameters can be adjusted to balance the load between different systems and to take full advantage of the common resource pool to achieve trunking gains from it. By adjusting idle mode parameters, the initial camping of the mobile can be directed to the desired radio system and unnecessar y handovers can be avoided. 300 Radio Network Planning and Optimisation for UMTS Table 5.7 Trunking gain in the case of load sharing between EDGE and WCDMA. The blocking probability used was 2% and the capacity of EDGE is the same as that of WCDMA. Number of WCDMA or WCDMA þEDGE Combined Trunking channels EDGE capacity gain [Erl] [Erl] [Erl] [%] Speech 60 49.6 99.3 107.4 8.2 64 kbps 10 5.1 10.2 13.2 29.7 144 kbps 5 1.7 3.3 5.1 53.4 384 kbps 2 0.2 0.4 1.1 145.2 5.3.2 Transmission Planning The aim of transmission planning is to connect BSs to BSCs or Radio Network Controllers (RNCs). Transmission media can be copper wire, coaxial cable, micro- wave links or fibre-optic line. Microwave links are flexible and can easily be located at the same places as BSs, whereas the copper wire solution will need more civil engin- eering work. Fibre-optic lines are deployed if there is a need for high-capacity links. The main difference between radio network and transmission planning is that in the latter case the network should be planned to fulfil the capacity demand s throughout the network’s lifespan. The topology of the transmission network determines its capacity, protection and expandability, theref ore topology changes should be avoided if possible. 5.3.2.1 Transmission Topologies Co-siting of WCDMA and GSM BSs means that the whole network will be affected, both access and core. Together with capacity growth, the content of the carried signal moves from circuit switched speech to packet data, both RT and NRT. Upgrading means important modifications in three areas. There could be topological changes, site configuration changes, and media upgrading and changes. The topologies used can be divided into five structures: chain, star, tree, loop and mesh. Chain topology can be used, for example, along highways but gives poor protection against faults. Loop and mesh topologies can provide good protection but they are quite expensive solutions. In any case a major upgrade of the transmission backbone for 3G systems is needed, compared with a GSM network. While a standard 4 þ 4 þ4 GSM site can be fitted to a single E1 trunk, a single WCDMA TRX (transmit and receive unit, or transceiver) delivers up to 1.5 Mbps of data on the Iub interface. In a typical urban European network, macro-cells with one carrier have been simulated to have an average throughput of 700–1000 kbps. Including 30% soft handover overhead, various protocol overheads, and so on, this adds up to a total of typically 1.5 Mbps per TRX, meaning a typical WCDMA 1 þ 1 þ1 site will need a transmission capacity of approximately 5 Mbps for 3G traffic. This is additional to existing GSM traffic. Note that GPRS does not contribute extra traffic, since it is handled via the GSM air interface, which has a direct mapping to the Abis interface (non-blocking). On the access network (Abis, Iub) the existing chain and loop topologies must be investigated and modified to accommodate the additional 3G traffic. This is likely to cause redesign of transmission topologies, or at least of traffic routing. In any case the issue leads to additional capacity needs. A factor of approximately 4 in additional capacity is needed. 5.3.2.2 Transmission Methods The transmission method defines the structure of the data and control stream in a transmission medium. In 2G networks the data and control streams were structured according to E1 or T1 trunks; the method was based on Time Division Multiplex WCDMA–GSM Co-planning Issues 301 (TDM). In 3G transmission networks the new method will be Asynchronous Transfer Mode (ATM) and, in the future, Internet Protocol Radio Access Network (IP RAN). The main difference between 2G and 3G traffic is assumed to be the burstiness of 3G services, as the packet data share will increase more than circuit switched data. The variety of services in 3G networks will also ben efit from the statistical multiplexing gain achieved in ATM networks. The delay characteristics of ATM networks are looser than those of TDM networks where in practice the delay is constant. In all-IP networks the delay characteristics will be specified. All-IP deployment enables the combining of different services and technologies under the same protocol, which will reduce system building and operating costs. 5.3.2.3 Transmission Sharing between Systems Sharing of the transmission systems between GSM and WCDMA would be useful in order to make full use of the existing hardware and to prevent the building of a totally new transmission network. By sharing hardware resources, some trunki ng gain can be achieved, and statistical multiplexing gain can also be obtained for 2G network services if the ATM or all-IP transmission network is deployed. In most cases there would be no strict necessity to change geographical topology and therefore sharing can be done by just adding or changing low-capacity devices to higher capacity ones. 5.3.3 Perception of Different Technologies by the End-user Technology comparison is a natural issue if the UMTS technology layer is included in an existing 2–2.5G network. As the netw ork needs to meet customer expectations from the end-user point of view, new technology must meet very good interworking standards from the beginning. This means especially inter-system handovers and cell reselection functionality along with similar or better Call Drop Rate (CDR) experience by the end-user. The property is important for services like speech where behaviour and quality is known from GSM and other cellular systems. Thus, the CDR must be the same or better. Let us consider the behaviour of speech quality in the situation when the mobile is moving out of the coverage area and it is not feasible to make a handover to a better cell either in the same or another technology. In this situation the desired behaviour of the mobile is to drop the connection after a similar period of bad quality as would have happened in the already used technology. Such behaviour represents an optimum between customer churn on one side and effective usage of technology on the other side. This should be adjusted by parameters and it is a natural optimisation target from the beginning. 5.3.4 Tight Usage of Frequency Spectrum by Different Technologies In some cases the frequency regulator issues a technology-independent licence. Thus, the operator can handle the spectru m owned quite freely. One possibility is thus that the spectrum is tightly used by different cellular technologies. Tight frequency use of the spectrum by different technologies brings challenges to the additional filtration solution for 2G BSs. The minimum coupling requirements between different BSs and different 302 Radio Network Planning and Optimisation for UMTS cellular systems are specified in [15]. Concrete solution of such cases depends on the spectrum situation of the specific case. 3GPP technical specifications for BS radio transmission and reception in FDD mode are in [15] and the Mobile Station (MS) is specified in [1]. The impact of narrowband technologies with tight frequency separation from the UMTS band is discussed in the next section. 5.4 Narrowband and WCDMA System Operation in Adjacent Frequency Bands Utilisation of WCDMA outside the 2 GHz UMTS core band – e.g., in the GSM1800 band or in the US Personal Communication System (PCS) 1900 MHz band – is now discussed. When the adjacent system to WCDMA is some narrowband mobile tele- communication system, such as GSM/EDGE, TDMA or narrowband CDMA, the evolution of mobile network systems from 2G to 3G requires flexible utilisation of available frequency bands. Operation of the WCDMA system when there are adjacent narrowband systems working in the same geographical area is, however, different from operation with the basic frequency allocation because of increased inter- ference between the narrowband system and the WCDMA system. In the 3GPP specifications the coexistence of WCDMA with the spectrally adjacent narrowband system has been taken into account. 3GPP Release 5 specifies both the characteristics for the WCDM A BS and the User Equipment (UE) respective MS when operating at the same band with the narrowban d system – the PCS system in this case ([1] and [15]). The most essential requirements covered by the specifications are blocking for the BS and out-of-band emission levels, as well as requirements for the narrowband blocking and intermodulation characteristics of the MS. New 3G multimedia services and enhanced capacity require more user bandwidth, which in turn causes decreased tolerance to interference from systems operating at adjacent frequency bands. This is due to the more demanding design of the wideband, linear components and also because a wideband receiver is more exposed to various interference sources. Also, the new frequency alloc ation schemes set additional requirements for the components. For example, the narrower duplex gap in the case of the PCS band sets more stringent requirements for duplex filters at the MS. In interference limited systems such as WCDMA, the increased interference causes a need for additional power in order to maintain the link quality, which in turn effects additional capacity and coverage degradation. In the adjacent channel operation of WCDMA and narrowband syst ems, several possible interference sources or interference mechanisms are present. The relative importance of various interference mechanisms is dependent on implementation of different network elements, locations of interfered and interfering sites with respect to each other, and the type and size of the cells. Performance degradation can be decreased by introducing guardbands around the WCDMA carrier, by frequency planning, by careful site and power planning or by co- siting with the interfering system. The general frequency allocation scenario showing WCDMA–GSM Co-planning Issues 303 the WCDMA band W WCDMA , the band allocated for the narrowban d system W NB and the guardband Df g are shown in Figure 5.16. By co-siting, it is possible to avoid the near–far effect between WCDMA and narrowband systems. The near–far effect here means, for example, that when the narrowband mobile is close to the WCDMA site and far away from its own site there will be uplink inter ference from the narrowband mobile to the WCDMA BS, and also that when the WCDMA MS is close to the narrowband BS there will be a large downlink interference component from the narrowband system to the WCDMA system. These same interference mechanisms also occur from the WCDMA system to the narrowband system, but the effect is smaller. Figure 5.17 shows some of the principal frequency allocation schemes associated with the WCDMA narrowband co- operation case. The upper scheme shows the situation where operator 1 has one WCDMA carrier and several narrowband carriers and the other operators have only narrowband carriers. The middle scheme shows the situations wher e operator 1 has only one WCDMA carriers and adjacent to that there are narrowband carriers of other operators. In the lower scheme operator 1 has two adjacent WCDMA carriers. In the first scheme, operator 1 can coordinate the usage of WCDMA and its own narrowband systems by co-siting them. By doing this the uncoordinated narrowband 304 Radio Network Planning and Optimisation for UMTS ∆ f g f … W N B W WCDMA ∆ f Figure 5.16 Frequency allocation with narrow and wideband systems including a guardband. (a) Operator2 Operator1Operator2 Operator1 WCDMA WCDMA (b) NB NB NB NB Operator3 Operator3 Operator3 Operator2 Operator1 Operator3 Operator2 Operator1 NB NB NB NB NB NB WCDMA WCDMA NB NB (c) Operator3 Operator1 WCDMA WCDMA WCDMA NB NB NB Operator3 NB Operator2 Operator1 Operator2 WCDMA Figure 5.17 Different frequency scenarios: (a) embedded scenario; (b) 5 MHz operation scenario; (c) 10 MHz operation scenario. The upper frequency allocations are for downlink and the lower ones are for uplink transmission directions. system is spectrally far away from the WCDMA system, decreasing the interference levels considerably. In the second case, operator 1 has only one WCDMA carrier just next to adjacent operators’ bands. In this case the interference is high, since the sites of different operators are usually not co-located. There is a possibility that the WCDMA and narrowband systems interfere each other, and such interfer ence has to be taken into account in radio network planning and dimensioning. Interference between narrowband and CDMA systems has also been studied in [8]–[10]. In the last frequency scenario, operator 1 has two adjacent WCDMA carriers. In this case the performance degradation of the WCDMA system due to additional interference can be avoided with inter-frequency handover between WCDMA carriers. 5.4.1 Interference Mechanisms Figure 5.18 shows the main interference mechanisms between WCDMA and narrowband systems. In the following sections these interference mechanisms will be discussed. More detailed information about different interference mechanisms can be found, for example, from [4]. 5.4.1.1 Adjacent Channel Interference Adjacent Channel Interference (ACI) results from non-ideal receiver filtering outside the band of interest. Even with an ideal transmitter emission mask, there is interference coming from adjacent channels because of ACI. Adjacent channel filtering and therefore ACI dep end on the implementation of analogue and digital filter ing at the MS in the downlink and at the BS in the uplink. Additionally, ACI is dependent on the power of the interfering system as well as the frequency offset between the interferer and the interfered systems. Usually, ACI is most severe when the channel separation between the own band and the interfering band is low. The effect of ACI decreases WCDMA–GSM Co-planning Issues 305 1) Adjacent Channel Interference 3) Adjacent C hannel Interfernece (ACI) 4) IMD at the WCDMA MS 6) WB emissions from NB BS NB BS WCDMA BS 5) Crossmodulati o (XMD) Adjacent channel interference IMD at the WCDMA MS Cross-modulation NB BS WB emissions from NB BS WCDMA BS Adjacent channel interference Figure 5.18 Main interference mechanisms between the narrowband system and the WCDMA system. rapidly outside the receive band, so ACI can be eliminated with an adequate guardband beside the WCDMA band. 5.4.1.2 Wideband Noise Wideband noise refers to all out-of-band emission components coming from the trans- mitter outside the wanted channel of the interfering system. It includes unwanted wideband emissions, thermal noise, phase noi se and spurious emissions as well as transmitter intermodulation. These interference mechanisms usually appear at fre- quencies which are far away from the band of interest and therefore these mechanisms can be considered as wideband. The allowed upper limit of wideband noise is usually described in the specifications of the narrowband system. 5.4.1.3 Intermodulation Distortion at the Receiver Intermodulation Distortion (IMD) is caused by non-linearities in the RF components of the receiver or transmitter. Intermodulation takes place in the non-linear component when two or more signal components reach it and the signal level is high enough for the operating point to be in the non-linear part of the component. When two or more signals are added together in the non-linear element, the resulting outcome from the element includes, in addition to the desired signal frequency, higher order frequencies caused by the higher order non-linearities. Third-order IMD is particularly problem- atic, because it is typically strongest and falls close to the band of interest. In the case of two interfering signals on frequencies f 1 and f 2 , in the proxim ity of the desired signal, third-order IMD products are those falling on frequencies 2f 1 À f 2 and 2 f 2 À f 1 (Figure 5.19). Higher order IMD products exist but are usually less strong. Usually, the receiver IMD is the most relevant source of intermodulation, since the active components in the receiver are less linear than those in the transmitter; therefore, only the receiver IMD is considered here. Furthermore, we can focus on the downlink, since the active components in the BS are more linear than those in the MS. This is because, when increasing the linearity of the receiver, the power consumption increases as well, which is usually more critical in the design of the MS. The IMD in the downlink is caused by the mixing of products of the narrowband BS with carrier frequencies f 1 and f 2 . Assuming that these frequencies have equal powers, so that P f 1 ¼ P f 2 , the third-order intermodulation power reduced to the input of the nonlinear element is given by: P in IMD ¼ 3 Á P i À 2 ÁIIP 3 ð5:13Þ 306 Radio Network Planning and Optimisation for UMTS f IMD =2f 2 -f 1 f 1 f 2 f Figure 5.19 Third-order intermodulation distortion. [...]... coverage Radio Network Planning and Optimisation for UMTS 314 USER DISTRIBUTION for operator 1 (all) (total = 400 users) OP2 OP1 11 66 760 00 OP1 OP2 OP1 12 OP2 66 7 560 0 Y-coordinate [m] OP2 OP1 2 3 OP2 1 OP2 66 75200 1 3 OP1 5 OP1 66 74800 OP1 7 2 OP1 OP2 OP2 7 OP2 8 4 OP1 9 6 9 8 OP2 6 10 OP1 OP2 66 74400 OP1 5 OP1 OP2 11 OP2 4 12 10 13 66 74000 384200 38 460 0 385000 385400 385800 3 862 00 X-coordinate [m] 3 866 00... site configuration, mobile terminal performance and traffic profile A cell is uplink capacity limited when it reaches its maximum permissible level of uplink load A cell is downlink capacity Radio Network Planning and Optimisation for UMTS Second Edition Edited by J Laiho, A Wacker and T Novosad # 20 06 John Wiley & Sons, Ltd 332 Radio Network Planning and Optimisation for UMTS limited when it reaches its maximum... masts and the narrower vertical antenna pattern The ray-tracing propagation model was used 5.4.5 Summary and Radio Network Planning Guidelines This concluding section describes some radio network planning aspects associated with the co-existence of a narrowband system and an adjacent WCDMA system in the same geographical area The main difference between radio network planning in the core UMTS band and. .. 5.4.3 showed that the number of users being served was reduced by 11% for the macro-cellular case and 21% for the micro-cellular case, which corresponds quite well with analytical results when the channel separation was 2 .6 MHz The out-of-band emissions from the narrowband BS (referred to as Radio Network Planning and Optimisation for UMTS 324 30 30 own own own own interf interf interf interf 0.5 km 0.5... was 500 in operator 1’s network and 800 in operator 2’s network Without narrowband interference With narrowband interference Without power limitation Operator 1 Operator 2 With power limitation Without power limitation With power limitation 4 46 7 76 452 778 351 761 422 763 probabilities were 84.4% and 95.4% So the service probability in macro-cells dropped by 6% when narrowband interference was introduced... 2  ð43 À 75Þ þ ð21 À 35Þ À 2  ðÀ10Þ ¼ À58 dBm (TxIMD) 43 À 60 :8 À 75 ¼ À92.8 dBm (WB) 43 À 75 À 67 ¼ À99 dBm (ACI) 43 À 64 :5 À 75 ¼ À 96. 5 dBm (WB) 43 À 75 À 30 ¼ 62 dBm (ACI) 43 À 75 þ 2  ð21 À 35Þ À 2  ðÀ10Þ À 5 À 0:5 ¼ À45:5 dBm (XMD) 2  ð43 À 75Þ þ ð21 À 35Þ À 2  ðÀ10Þ ¼ À58 dBm (TxIMD) Radio Network Planning and Optimisation for UMTS 310 Interference from NB MS to WCDMA BS Interference from... 25|11, 26| 10, 27|9, 28|8, 29|7, 30 |6, 31|5, 32|4, 33|3, 34|2 and 35|1 Channel 1 corresponds to the carrier that is closest to the WCDMA carrier, and channel 15 is the farthest, with 5.4 MHz channel separation from the WCDMA carrier The capacity without the downlink link-specific power limitation when narrowband interference is not present was 4 46 for the macro-rcell network and 7 76 for the microcell network. .. needed for 12.2-kbps service for operator 1 (left) and operator 2 (right) with no narrowband interference from the adjacent operator In the next simulation case the effect of narrowband interference from operator 2’s narrowband micro-cellular network to operator 1’s WCDMA macro-cell network (Case 1 in Figure 5.24) and from operator 1’s narrowband macro-cellular network to operator 2’s WCDMA micro-cell network. .. present Downlink coverage of 12.2-kbps service is 99.9% Radio Network Planning and Optimisation for UMTS 3 16 Figure 5.27 Link powers needed in WCDMA macro-cells (operator 2) when narrowband interference is not present Downlink coverage of 12.2 kbps service is 98.3% CDF of required power per link for Operator 1 CDF of required power per link for Operator 2 100 100 90 90 80 70 70 Probability [%] Probability(%)... BS, and (3) the carrier separation between the own WCDMA carrier and the narrowband carrier Also, the antenna pattern of the narrowband system as well as its Figure 5. 36 Link powers needed in WCDMA macro-cells (operator 1) when narrowband interference is present Downlink coverage of 12.2 kbps service is 83.8% Black areas indicate locations that cannot be served 322 Radio Network Planning and Optimisation . 385800 3 862 00 3 866 00 387000 387400 387800 66 74000 66 74400 66 74800 66 75200 66 7 560 0 66 760 00 USER DISTRIBUTION for operator 1 (all) (total = 400 users) OP1 1 OP1 2 OP1 3 OP1 4 OP1 5 OP1 6 OP1 7 . uncoordinated narrowband 304 Radio Network Planning and Optimisation for UMTS ∆ f g f … W N B W WCDMA ∆ f Figure 5. 16 Frequency allocation with narrow and wideband systems including a guardband. (a) Operator2 Operator1Operator2 Operator1 WCDMA WCDMA (b) NB NB NB NB Operator3 Operator3 Operator3 Operator2 Operator1 Operator3 Operator2 Operator1 NB NB NB NB NB NB WCDMA WCDMA NB NB (c) Operator3 Operator1 WCDMA WCDMA WCDMA NB NB NB Operator3 NB Operator2 Operator1 Operator2 . the left-hand side of the figure at carriers 4 and 5, which are 3.2 and 3.4 MHz away from the WCDMA centre frequency. 314 Radio Network Planning and Optimisation for UMTS 384200 38 460 0 385000