Presentation to Radiocommunications Agency 16 June 2000 BFWAtg(00)39

Structure of the presentation u Scope and objectives of the study u Interference analysis (worst case) u Statistical modelling and analysis u Conclusions and recommendations

Objective of the Study u To determine co-existence requirements for BWFA services sharing the same spectrum in adjacent geographic areas

Scope u Identify the effect of modified interference criterion on co-ordination requirements –Interference limit 6dB below the noise floor u Identify the effect of applying different downtilts to PMP BSs on interference analysis u Identify the effect of different PMP cell sectorisation on interference analysis

Approach taken u Determine the modified co-ordination distances from the worst case scenarios u Statistical modelling to determine the effect of antenna downtilting on interference analysis u Statistical modelling to determine the effect of cell sectorisation on interference analysis

Interference Scenarios u PMP Base station to PMP base station u PMP Base station to subscriber station u Subscriber station to subscriber station u Subscriber station to PMP base station u Between very high density networks

Base to Base Co-ordination: u For reference base station, PFD limit at the service area boundary should not exceed: –95.5 dBW/MHz/m 2 at 42 GHz –99.5 dBW/MHz/m 2 at 28 GHz u Co-ordination distance from boundary is: –13.5 km at 42 GHz –21 km at 28 GHz

Subscriber station interference u With ATPC, LOS co-ordination distances from the service area boundary are: –7.5 km at 42 GHz –12.5 km at 28 GHz

Interference from very high density networks u Co-ordination distances are smaller due to smaller cells and lower EIRPs u To minimise co-ordination of individual stations, operators should avoid co-channel, co-polar operation within 5 km of adjoining service area boundaries

PMP BS antenna downtilt: 1 u Original analysis performed with downtilt equal to 9 degrees u In this study, the BS antenna downtilt was varied between 0 and 9 degrees u Monte Carlo statistical analysis conducted to determine the impact of different downtilts on interference environment

PMP BS antenna downtilt: 2 u Results of the study show that: –Interference from multiple PMP BS interferers operating in adjacent geographic area will be within the desired limits providing the BS antenna downtilt is not less than 8 degrees u Note: using different antenna RPE may have an impact on the conclusions

PMP cell sectorisation: 1 u Range of PMP cell sector widths modelled –30°, 60°, 90° and 120° sectors investigated u Statistical analysis conducted – Tx power adjusted to maintain EIRP level –Antenna RPE and gain adjusted –Other parameters maintained at the same level

u Statistical analysis has confirmed that: –There is a higher probability of suffering interference from PMP BS in adjacent geographic areas if wider sector cells are deployed –The highest probable interference levels for different sector widths deployed do not differ significantly PMP cell sectorisation: 2

–Providing the co-ordination requirements are satisfied, the interference levels experienced by adjacent geographic region BFWA station will be acceptable regardless of the PMP cell sector width deployed PMP cell sectorisation: 3

Conclusions: 1 u Co-ordination of individual stations required if boundary PFD exceeds: / dBW/MHz/m 2 at 42 GHz / dBW/MHz/m 2 at 28 GHz u Typical Line of Sight co-ordination distances: / 13.5 km at 42 GHz (4.5 km smaller than for the original interference criteria) / 21 km at 28 GHz (6.5km smaller than for the original interference criteria)

Conclusions: 2 u Typical subscriber LoS co-ordination distance, with ATPC: / 7.5 km at 42 GHz (2.5km smaller than for the original interference criteria) / 12.5 km at 28 GHz (3.5km smaller than for the original interference criteria) u Co-channel, co-polar operation should be avoided within 5 km of service boundary

Conclusions: 3 u Monte Carlo analysis has concluded that co-ordination requirements are valid: –If elevated PMP BS antennas are downtilted by 8° or more (providing an antenna complying with ETSI EN standards is used) –Regardless of the PMP cell sector width deployed in the range between 30° and 120°

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