Includes Installation Instructions
Implementation: July 2009
TABLE OF CONTENTS
1. PURPOSE 3
2. Scope 3
3. Notes to Design & Installation ContractorS 3
4. OHS&E ISSUES 3
5. DESIGN SPECIFICATION 3
5.1. General DAS Description 3
5.1.1. Passive DAS 3
5.1.2. Active DAS 3
5.2. Operating Frequency Bands 3
5.2.1. Alternative frequency ranges 3
5.3. DAS Capability 3
5.3.1. Passive DAS 3
5.3.2. Active DAS 3
5.4. Target Coverage Area 3
5.5. RF Levels Required 3
5.5.1. GSM900 3
5.5.2. 3G850 3
5.5.3. DCS1800 3
5.5.4. 3G2100 3
5.6. Handover Zone 3
5.7. DAS Configuration 3
5.7.1. Passive DAS Interconnect Ports 3
5.7.2. Active DAS Interconnect Ports 3
5.8. Radiated Power Levels 3
5.8.1. Passive DAS 3
5.8.2. Active DAS 3
5.9. Electromagnetic Immunity 3
5.10. Base Station Power Levels 3
5.11. Maximum Signal Received by MS/UE 3
5.12. Minimum Allowable Path Loss 3
5.12.1. Passive DAS 3
5.12.2. Active DAS 3
5.13. Propagation Model 3
5.14. Measured performance of installed DAS 3
5.14.1. Return loss 3
5.14.2. Passive intermodulation 3
5.15. Cable and Component Labelling 3
5.16. Preferred Material List 3
5.17. Other Equipment Specifications 3
5.17.1. Characteristic impedance 3
5.17.2. VSWR 3
5.17.3. Intermodulation 3
5.17.4. Coaxial connector types 3
5.17.5. Patch cables 3
6. DELIVERABLES 3
6.1. Documentation 3
6.2. Preliminary Design Documentation 3
6.3. Detailed Design Documentation 3
6.4. Installation Documentation 3
6.5. Contractor/Builder initiated DAS 3
7
8. Attachment-A: DAS INSTALLATION INSTRUCTIONS 3
8.1. Passive Backbone 3
8.2. Active Backbone 3
8.3. Floor Cabling 3
8.3.1. Feeder Cable Mounting (non radiating cable) 3
8.3.2. Radiating Cable Mounting 3
8.3.3. Mounting of Omni Antennas 3
8.3.4. Mounting of Panel Antennas 3
8.3.5. Other Arrangements 3
9. Attachment-B: TEST RESULTS – PASSIVE DAS 3
9.1. RF Sweeps 3
9.2. Insertion Loss 3
9.3. Passive Intermodulation Testing 3
9.3.1. Dynamic testing 3
1. PURPOSE
Distributed Antenna Systems (DAS) are the in-building cabling, distribution and radiating elements required for enhanced In-Building Coverage (IBC) for wireless services.
This specification outlines design and acceptance into service requirements for a DAS.
2. Scope
This document applies to the design of IBC DAS to which a mobile telecommunications carrier proposed to connect its equipment. Where capacity issues require a DAS to be sectorised within a site, this document applies to each sector.
Clauses 5.3 and 5.5 should be used for mobile carrier design requirements for DASs built by other operators.
3. Notes to Design & Installation ContractorS
The RF design contractor shall develop all DAS Design Documentation in accordance with this document
A DAS shall only be accepted into operation when the installation contractor verifies to one of the licensed mobile carriers that the specifications defined in this document are met.
4. OHS&E ISSUES
Issues of RF radiation hazards are included in the design process.
This DAS Design Specification Document does not override any general or project specific OHS&E requirements. Where there seems to be a contradiction, more stringent requirement should be applicable until the issue is discussed and resolved among “Sharing Carriers”.
5. DESIGN SPECIFICATION
5.1. General DAS Description
The Distributed Antenna System (DAS) may be either passive:
typically composed of standard and radiating coaxial cables in various diameters (such as 3/8”, 1/2”, 7/8”, etc.), couplers and power splitters which are employed to branch the base station power to indoor type omni and/or panel antennas in remote locations;
or active:
typically composed of point-to-point optical fibre cables connecting one or more local fibre-optic interfaces located in the base station to one or more AC or DC power operated active heads in remote locations. The remote active heads in turn are each connected to one or more antennas, possibly via an additional amplifier.
In some cases the DAS can be hybrid, i.e. having both passive and active DAS segments.
In a DAS, RF signal is transmitted in both directions (uplink from mobile towards a base station, and downlink from a base station towards a mobile).
5.1.1. Passive DAS
A passive DAS is typically divided into two main components:
• the backbone feed system which forms the distribution to each floor or area; and
• the floor/area cabling.
The backbone is generally composed of cables, splitters and couplers. The preferred network topology is for groups of floors/areas (up to 4) to be fed from a multi-way splitter, which in turn is fed from a trunk cable from the BTS (or from a higher level splitter where there are more than 4 floors/areas).
The floor cabling can be a combination of any of radiating cable, coaxial cable, fibre-optic remote heads, antennae and terminations.
5.1.2. Active DAS
An active DAS typically has an interface unit which converts RF signals to optical signals. This interface unit is typically co-located with the BTS equipment. Optical fibre distribution is used to feed remote active heads which convert the optical signals back to RF signals which are then connected to individual antennas or to a small passive distribution system.
Active systems may be multi-band, e.g. a tri-band system could have 3G850, DCS1800 and 3G2100 amplifiers in a common remote head.
5.2. Operating Frequency Bands
The radio equipment connected to the Distributed Antenna System shall operate in the 800/900 MHz bands (825 – 960 MHz), 1800 MHz band (1710 – 1880 MHz) and the 2100 MHz band (1910 – 2170 MHz) in accordance with the relevant ITU, ETSI and 3GPP specifications.
ACMA is considering release of 2500 ~ 2690 MHz band for LTE deployment.
The design shall generally specify the use of components which operate over the frequency range 825 – 960 and 1710 - 2170 MHz. Antennas and radiating cable shall operate over the frequency ranges 825 – 960 and 1710 –2690 MHz.
5.2.1. Alternative frequency ranges
Where provision is required for non-cellular services, specify components that cover the required frequency range.
When a DAS is required to carry wireless LAN signals (Wi-Fi or IEEE 802.11 at 2.4 GHz), designers shall comply with DCRB029.
If coverage of Mobile TV or UHF private mobile radio systems is needed, specify components which cover the 380 – 2200 MHz range. Note that this requirement is incompatible with provision for wireless LAN at 2.4 GHz.
If coverage of Mobile TV (700 MHz Band) or UHF private mobile radio (400 MHz Band) systems is needed, specify components which cover the required additional bands which may extend to 380 – 820 MHz range.
5.3. DAS Capability
5.3.1. Passive DAS
Generally a passive DAS shall be capable of simultaneous operation of 3G850, GSM900/UMTS 900, GSM1800 and 3G2100 radio systems in accordance with Table 5-1. Where there are other “Sharing Carriers” with different requirements, these different requirements need to be considered among “Sharing Carriers” to establish an agreed DAS design specification prior to start of any DAS design work.
Technology / No of RF channels / Maximum input power per channel in the systemGSM900/UMTS900 / 9 / +40 dBm
GSM1800 / 9 / +40 dBm
3G850 / 4 / +40 dBm (+30 dBm CPICH power)
3G2100 / 8 / +40 dBm (+30 dBm CPICH power)
Table 5-1 DAS capability requirements
5.3.2. Active DAS
The number of sharing Carriers and the number of channels per Carrier in each frequency band shall be established prior to the commencement of the design.
The design shall assume that all channels in every frequency band are in operation simultaneously and at maximum forward power.
5.4. Target Coverage Area
The Target Coverage Area shall be marked on copies of the site plan and floor plans and agreed prior to commencement of the design.
5.5. RF Levels Required
Clauses 5.5.1 to 5.5.4 prescribe criteria for mobile station receive signal levels required at different locations within buildings and outside the Target Coverage Area, to a confidence level of 95%.
These are minimum levels for In building Coverage DAS installations.
When survey measurements show that the received power levels from nearby macro network base stations are greater than the minimum levels specified for GSM900/ UMTS 900 and DCS1800, and are greater than 6 dB below the minimum levels specified for 3G850 and 3G2100, obtain confirmation and approval of the required IBC levels from a licensed mobile carrier engineer prior to the commencement of the DAS design.
5.5.1. GSM900/UMTS 900
The design shall provide for GSM900/ UMTS900 at the following levels (received BCCH power levels from a +40 dBm transmitter, measured with a unity gain omni antenna and achieve 95% of the coverage objectives):
(a) > -65 dBm within 2 m of the perimeter walls and windows inside the premises;
(b) > -70 dBm in the building core;
(c) > -75 dBm in the basement car parks;
(d) < -90 dBm at ground level outside the building.
5.5.2. 3G850
The design shall provide for 3G850 at the following levels (received CPICH power levels from a +40 dBm transmitter (+30 dBm CPICH power), measured with a unity gain omni antenna and achieve 95% of the coverage objectives):
):
(a) > -85 dBm within 2 m of the perimeter walls and windows inside the premises;
(b) > -90 dBm in the building core;
(c) > -95 dBm in the basement car parks;
(d) < -110 dBm at ground level outside the building.
(e) Where ever possible a margin of at least 6dB above the existing macro cell coverage should be used as a design target for all cases listed above.
5.5.3. DCS1800
The design shall provide for DCS1800 at the following levels (received BCCH power levels from a +40 dBm transmitter, measured with a unity gain omni antenna and achieve 95% of the coverage objectives):
):
(a) > -75 dBm within 2 m of the perimeter walls and windows inside the premises;
(b) > -80 dBm in the building core;
(c) > -85 dBm in the basement car parks;
(d) < -100 dBm at ground level outside the building.
5.5.4. 3G2100
The design shall provide for 3G2100 at the following levels (received CPICH power levels from a +40 dBm transmitter (+30 dBm CPICH power), measured with a unity gain omni antenna and achieve 95% of the coverage objectives):
:
(a) > -85 dBm within 2 m of the perimeter walls and windows inside the premises;
(b) > -90 dBm in the building core;
(c) > -95 dBm in the basement car parks;
(d) < -110 dBm at ground level outside the building.
(e) Where ever possible a margin of at least 6dB above the existing macro cell coverage should be used as a design target for all cases listed above.
5.6. Handover Zone
RF levels shall be sufficient to facilitate both-way handovers with the external network at locations agreed on the target Coverage Area.
Handovers to/from external fast moving mobiles need to be avoided (except in tunnels). The design should ensure that RF levels specified in clause 6.5 at ground level outside the building are met.
5.7. DAS Configuration
The DAS shall be passive wherever possible utilising the RF power of the base stations to the fullest possible extent. Active DAS sections shall be included only if there are installation constraints, or available RF power is not sufficient.
Access to the DAS ports shall be from a communications room with sufficient accommodation for the base station and network transmission equipment.
The design shall satisfy the installation requirements specified in Attachment A.
The distribution for each floor in a multi-storey building shall commence in a common communications riser shaft.
5.7.1. Passive DAS Interconnect Ports
Provide four duplex ports to the DAS for multi-Carrier sharing. Each port shall be capable of accepting up to 80 W composite transmit power, with a maximum power of 10 W per individual channel (e.g. 8 x 10 W into each of the 4 inputs, at Measurement point 1 in Figure 5-1).
5.7.2. Active DAS Interconnect Ports
Provide a duplex port for each sharing Carrier for each frequency band which that Carrier has notified as a requirement.
5.8. Radiated Power Levels
The composite input power to any antenna in a DAS shall not exceed +17 dBm per Sharing Carrier without approval.
In no case shall the combined power level from all transmitters cause the power density to exceed the ARPANSA General Public power flux density (“Maximum exposure levels to radio frequency fields – 3 kHz to 300 GHz”, Radiation Protection Series No. 3, Australian Radiation Protection and Nuclear Safety Agency.) within 100 mm of any antenna.
To prevent interference to other existing equipment, the electric field strength shall not exceed 3 V/m, measured at a location nearest to the equipment under consideration.
5.8.1. Passive DAS
Assume a configuration of 4 operators each feeding 80 W composite power at 900 MHz into the multi-network combiner when assessing radiated power levels for this clause.
If any Carrier is licensed for UMTS only, the power into each antenna may be calculated assuming that the port occupied by the UMTS-only Carrier is fed with 80 W at 2100 MHz.
When 3G2100 channels are coupled to the DAS at an input other than the multi-network combiner (e.g. at a cross-band coupler in the riser of a high-rise DAS), assume a maximum of 8 x 10 W channels (at 2100 MHz) inserted at that input when assessing radiated power levels.
5.8.2. Active DAS
Assume that all active devices connected to an antenna are operating at their maximum rated composite output power per frequency band.
5.9. Electromagnetic Immunity
Designers shall ensure that the field strength levels in Table 5-2 are not exceeded in the areas or at the equipment locations specified.
Equipment or Location / Area / Field strength limitHospitals / Critical care medical equipment / 1 V/m rms
Institutions for the Hearing Impaired / 1 V/m rms
Domestic Equipment / Location of domestic electrical equipment, e.g. radio & television receivers, IT equipment. / 3 V/m rms
Explosives and Fuel / Electro explosive devices – quarries, blasting sites. Military – consult TRL. Petroleum or aviation gas fuel sites. / 9 V/m rms
Table 5-2 EMI Limits
As a guide, Table 5-3 indicates the distances from an antenna that the 1, 3 and 9 V/m electric field strength limits are reached (to within 0.1 m). Note that, for a given EIRP, the electric field strength at a given distance is independent of frequency and varies linearly with distance.