wireless backhaul – spectrum, technology and policy · microwave backhaul microwave backhaul use...

WIRELESS BACKHAUL – SPECTRUM,TECHNOLOGY AND POLICY

Muditha Gunasinghe

Deputy Director/Spectrum Management

Telecommunications Regulatory Commission of Sri Lanka

SATRC Workshop on Spectrum, 16-18 August 2017, Islamabad, Pakistan 1

WHAT IS THE BACKHAUL ?

Backhaul portion of the network comprises theintermediate links between the Core Network,or backbone and the small subnetworks at the "edge"of the entire hierarchical network.

Taking information in-between point A to point B.


INTRODUCTION

Over the last few years, wireless networks experiencedunexpected demands for higher data rates and QoS.

Specially, With the rapid deployment of 3G and 4G mobile servicesbring unexpected demand in data traffic, which in turn puts astrain on existing cellular networks.

Demand for more available capacity felt more than in theBackhaul.

Operators can choose one of three physical mediums; copper, fiberor microwave for their Backhaul networks

Microwave usage nearly 50% of global backhaul deployments

Over the last few years, wireless networks experiencedunexpected demands for higher data rates and QoS.

Specially, With the rapid deployment of 3G and 4G mobile servicesbring unexpected demand in data traffic, which in turn puts astrain on existing cellular networks.

Demand for more available capacity felt more than in theBackhaul.

Operators can choose one of three physical mediums; copper, fiberor microwave for their Backhaul networks

Microwave usage nearly 50% of global backhaul deployments


MICROWAVE VS FIBER


MICROWAVE BACKHAUL

Microwave backhaul use is higher in emerging market.

Point to multi point is the fastest and lowest cost way to buildmicrowave backhaul networks

It has significant spectrum efficiency and backhaul solutions cost50% less.

Microwave is the predominant form of backhaul for mobile cellsites.

Telecom operators and other users are more like to have theirowned backhaul networks rather than going for hiring fiber links

Low OPEX and high availability

High hiring cost for fiber links

TRCSL encouraging operators to go for fiber by regulating the fibertariff in near future.

Microwave backhaul use is higher in emerging market.

Point to multi point is the fastest and lowest cost way to buildmicrowave backhaul networks

It has significant spectrum efficiency and backhaul solutions cost50% less.

Microwave is the predominant form of backhaul for mobile cellsites.

Telecom operators and other users are more like to have theirowned backhaul networks rather than going for hiring fiber links

Low OPEX and high availability

High hiring cost for fiber links

TRCSL encouraging operators to go for fiber by regulating the fibertariff in near future.


REQUIREMENTS ON BACKHAUL

Requirements on backhaul in the mid term (2015-2020)

Backhaul requirements for dense urban areas

capacity requirement of one to a few Gbit/s per basestation

range of 200 meters to 2 km.

Backhaul requirements for rural areas

Capacity from a few to several hundred of Mbit/s

range a few km up to 15 km

Requirements of wireless backhaul used for fronthaul links

high speed digital connection between the central unitand remote radio unit

capacity requirements in the range of 1-10 Gbit/s

Requirements on backhaul in the mid term (2015-2020)

Backhaul requirements for dense urban areas

capacity requirement of one to a few Gbit/s per basestation

range of 200 meters to 2 km.

Backhaul requirements for rural areas

Capacity from a few to several hundred of Mbit/s

range a few km up to 15 km

Requirements of wireless backhaul used for fronthaul links

high speed digital connection between the central unitand remote radio unit

capacity requirements in the range of 1-10 Gbit/s


REQUIREMENTS ON BACKHAUL

Backhaul requirements in the long term (2020-2030) Backhaul must be able to transport more traffic to accommodate the increases in data

throughput required by users.

Backhaul must also transport this traffic with low latency, in order to prevent a negativeimpact on the users’ quality of experience (QoE).

Backhaul facilities should be cost effective, easy to install, and have a small footprint, as alarge number of new small cells are expected to address the demand for mobile broadbandgrowth.

To adapt to a challenging environment (lamp post, traffic light, etc.), the use of a newform factor antenna may be necessary.

Technique to be used Automatic Transmit Power Control (ATPC)

Modulation: using higher modulation formats; applying adaptive modulation technique

Bandwidth adaptive systems

Polarization: polarization multiplexing

Multiple Input Multiple Output (MIMO): using multiple antennas at the transmitter and/orreceiver

Full duplex radios (echo cancellation)

Asymmetrical point-to-point links

Backhaul requirements in the long term (2020-2030) Backhaul must be able to transport more traffic to accommodate the increases in data

throughput required by users.

Backhaul must also transport this traffic with low latency, in order to prevent a negativeimpact on the users’ quality of experience (QoE).

Backhaul facilities should be cost effective, easy to install, and have a small footprint, as alarge number of new small cells are expected to address the demand for mobile broadbandgrowth.

To adapt to a challenging environment (lamp post, traffic light, etc.), the use of a newform factor antenna may be necessary.

Technique to be used Automatic Transmit Power Control (ATPC)

Modulation: using higher modulation formats; applying adaptive modulation technique

Bandwidth adaptive systems

Polarization: polarization multiplexing

Multiple Input Multiple Output (MIMO): using multiple antennas at the transmitter and/orreceiver

Full duplex radios (echo cancellation)

Asymmetrical point-to-point links


TOPOLOGY OF THE NETWORKS

Point-to-point links

LoS backhaul

LoS backhaul, in particular at millimetre waves, allows the reuse of thesame frequencies for two or more PP links at the same location or at veryclose locations

NLoS backhaul

Solution for cluttered urban environments

NLoS-Upto 6GHz and Near LoS upto 10GHz

Point-to-multipoint networks

Multipoint-to-multipoint networks

Mesh topology

Self-backhauling in mobile frequency bands

Point-to-point links

LoS backhaul

LoS backhaul, in particular at millimetre waves, allows the reuse of thesame frequencies for two or more PP links at the same location or at veryclose locations

NLoS backhaul

Solution for cluttered urban environments

NLoS-Upto 6GHz and Near LoS upto 10GHz

Point-to-multipoint networks

Multipoint-to-multipoint networks

Mesh topology

Self-backhauling in mobile frequency bands


SELF-BACKHAULING: THE CONCEPT

Self-backhauling defined as whenthe access (BS-MS) and thebackhaul(BS-BS or BS-Network)share the same wirelesschannel

Sharing options of the wirelesschannel resources (Time,Frequency, and Space):

a)Orthogonal (no reuse)

b)Partial reuse

c)Full reuse (one)

Source: InterDigital Confidential and Proprietary © 2015 InterDigital, Inc.

SATRC Workshop on Spectrum, 16-18 August 2017, Islamabad, Pakistan

Self-backhauling defined as whenthe access (BS-MS) and thebackhaul(BS-BS or BS-Network)share the same wirelesschannel

Sharing options of the wirelesschannel resources (Time,Frequency, and Space):

a)Orthogonal (no reuse)

b)Partial reuse

c)Full reuse (one)

Source: InterDigital Confidential and Proprietary © 2015 InterDigital, Inc.

9

WIRELESS BACKHAUL ADOPTION

Globally, an increasing percentage of new backhaul investment is inmicrowave.

It depends on;

spectrum and license costs.

the extent of existing copper and fiber resources.

geographical condition.

availability of equipment

Microwave having its ease of deployment and greater range, performanceand flexibility.

CAPEX is offset by low OPEX, making microwave more cost effective.

Globally, an increasing percentage of new backhaul investment is inmicrowave.

It depends on;

spectrum and license costs.

the extent of existing copper and fiber resources.

geographical condition.

availability of equipment

Microwave having its ease of deployment and greater range, performanceand flexibility.

CAPEX is offset by low OPEX, making microwave more cost effective.


BACKHAULS IN SRI LANKA

All 3 fixed line operators and 5mobile operators have their ownedmicrowave backhaul networks.

Sri Lanka Telecom (SLT) and DialogBroadband Network (DBN) havetheir own fiber as well.

SLT leases their fiber to otheroperators and other users.

Lanka Communication Services(Pvt) Ltd (Lanka Com) leases theirmicrowave backhaul to third-party.

All 3 fixed line operators and 5mobile operators have their ownedmicrowave backhaul networks.

Sri Lanka Telecom (SLT) and DialogBroadband Network (DBN) havetheir own fiber as well.

SLT leases their fiber to otheroperators and other users.

Lanka Communication Services(Pvt) Ltd (Lanka Com) leases theirmicrowave backhaul to third-party.


FREQUENCY BANDS

Frequency Bands allocated for wireless backhaul networks –4GHz, 5.8GHz, 6GHz, 7.1GHz, 7.4GHz, 7.9GHz, 11GHz, 13GHz,15GHz, 18GHz, 23GHz, 26GHz and 38GHz

Bandwidths – 1.75/3.5/7/14/28/56MHz

10.5GHz and 28GHz bands are allocated for point-to-multi pointsapplications

Bandwidths – 3.5/7/14/28/56MHz

70/80GHz band was very recently allocated to high capacityshort distance applications

Bandwidths – 250/500MHz

VHF and UHF frequecy bands are allocated for soundbroadcasters for Studio Transmission Links (STL)

Bandwidths – 200/300kHz

Frequency Bands allocated for wireless backhaul networks –4GHz, 5.8GHz, 6GHz, 7.1GHz, 7.4GHz, 7.9GHz, 11GHz, 13GHz,15GHz, 18GHz, 23GHz, 26GHz and 38GHz

Bandwidths – 1.75/3.5/7/14/28/56MHz

10.5GHz and 28GHz bands are allocated for point-to-multi pointsapplications

Bandwidths – 3.5/7/14/28/56MHz

70/80GHz band was very recently allocated to high capacityshort distance applications

Bandwidths – 250/500MHz

VHF and UHF frequecy bands are allocated for soundbroadcasters for Studio Transmission Links (STL)

Bandwidths – 200/300kHz


SPECTRUM ASSIGNMENT

Spectrum is assigned on link basis and charge accordingly.

License Fee consists of two parts

Frequency Charge and Power Charge

Frequency charge depends on frequency band and assigned bandwidth.

Power charge is depends on the output power of the transmitter.

Assignment on first come fist serve basis

Telecom operators should propose their frequency requirement byaccessing TRCSL database and they should make sure non-interference toexisting users.

If there is any interference the last in should vacate.

For others TRCSL assigns frequencies for backhaul networks.

Nearly 5 Billion LKR (35 Million USD) revenue is collected yearly byfrequencies for backhaul networks.

Spectrum is assigned on link basis and charge accordingly.

License Fee consists of two parts

Frequency Charge and Power Charge

Frequency charge depends on frequency band and assigned bandwidth.

Power charge is depends on the output power of the transmitter.

Assignment on first come fist serve basis

Telecom operators should propose their frequency requirement byaccessing TRCSL database and they should make sure non-interference toexisting users.

If there is any interference the last in should vacate.

For others TRCSL assigns frequencies for backhaul networks.

Nearly 5 Billion LKR (35 Million USD) revenue is collected yearly byfrequencies for backhaul networks.


LICENSE FEE FOR BACKHAUL FREQUENCIES

License Fee contains two parts.

Frequency fee depends on frequency band and assigned bandwidth

Power charge depends on output power of the transmitter

Frequency Charges Power ChargesFrequency

BandFrequency Range Fees Payable per kHz

of assigned bandwidthof emission(Rs.)

VLF 3- 30 kHz 375.00LF 30 -300 kHz 375.00MF 300- 3000 kHz 375.00

TransmitterOutputPower

(Watts))

Fees payable per Annum (Rs.)

HFand below

VHFBand I & II

UHF Band I & IISHF Band I, II III&EHF Band I,II,II

III,IV,V,VI

SATRC Workshop on Spectrum, 16-18 August 2017, Islamabad, Pakistan

MF 300- 3000 kHz 375.00HF 3 -30 MHz 375.00

VHF 30 - 100MHz 225.00VHF 100- 300 MHz 375.00UHF 300 -1000 MHz 125.00UHF 1000 -3000 MHz 18.75SHF 3-9 GHz 10.00SHF 9-20 GHz 7.50SHF 20-30 GHz 5.00EHF I 30-40GHz 2.50EHF II 40-50 GHz 2.00EHF III 50-60 GHz 1.50EHF IV 60 -70GHz 1.00EHF V 70- 90 GHz 0.50EHF VI 90-300 GHz 0.25

TransmitterOutputPower

(Watts))< 1(note4)

750.00 3,125.00 2,500.00

1-5 1,875.00 3,750.00 3,125.005-10 3,750.00 5,625.00 5,000.0010-15 5,625.00 7,500.00 5,625.0015-20 5,625.00 9,375.00 7,500.0020-25 5,625.00 18,750.00 12,500.0025-30 9,375.00 31,250.00 18,750.0030-50 9,375.00 50,000.00 37,500.0050-75 12,500.00 62,500.00 Rs.3,750.00 per

additional Watt orpart thereof above50 Watts

75-100 18,750.00 125,000.00100-150 50,000.00 Rs.3,750.00 per

additional Watt orpart thereof above100 Watts

150-500 93,750.00500-1000 187,500.001000 and

aboveRs.500.00 per

additionalWatt or part

thereof above1000 Watt

14

EXAMPLE ON LICENSE FEE CALCULATION

Consider assignment in 23GHz band for full duplex link with 28MHzbandwidth and links radios with output power of 1W.

Frequency Charge

Frequency is in the range of 20-30GHz (SHF III) ie. Rs.5.00 per kHz

Frequency charge for single frequency = Rs. 28x1,000x5.00 = Rs.140,000.00

Frequency charge for duplex frequency = Rs.140,000.00x2=Rs.280,000.00 (peryear)

Power Charge

Output power is in the range of 1-5W. ie. Rs.3,125.00 for SHF III

Power Charge= Rs.3,125.00x2= Rs.6,250.00 (per year)

Total license fee= Rs. 280,000.00+6,250.00= Rs.286,250.00 (per year)

Consider assignment in 23GHz band for full duplex link with 28MHzbandwidth and links radios with output power of 1W.

Frequency Charge

Frequency is in the range of 20-30GHz (SHF III) ie. Rs.5.00 per kHz

Frequency charge for single frequency = Rs. 28x1,000x5.00 = Rs.140,000.00

Frequency charge for duplex frequency = Rs.140,000.00x2=Rs.280,000.00 (peryear)

Power Charge

Output power is in the range of 1-5W. ie. Rs.3,125.00 for SHF III

Power Charge= Rs.3,125.00x2= Rs.6,250.00 (per year)

Total license fee= Rs. 280,000.00+6,250.00= Rs.286,250.00 (per year)


BACKHAUL NETWORK EVOLUTION IN SRI LANKABACKHAUL NETWORK EVOLUTION IN SRI LANKA


BACKHAUL NETWORK 2007

TECHNOLOGY

1. TDM Technology was used for backhauling

2. Both SDH and PDH were used

3. Major building block of the PDH – E1

4. Major building block of the SDH – STM 1

5. Cross Polarization Interference Cancellation (XPIC) technology was used to double the capacity

MODULATION1. Maximum Modulation of SDH 128 QAM

2. Maximum Modulation of PDH 16 QAM

1. Maximum Capacity SDH – STM-1 ( Equivalent to 155 Mbps)

2. Maximum Capacity – 16E1 ( Equivalent to 34 Mbps)CAPACITY

1. Maximum Capacity SDH – STM-1 ( Equivalent to 155 Mbps)

2. Maximum Capacity – 16E1 ( Equivalent to 34 Mbps)

BANDWIDTH1. Required BW for SDH – 28 MHz

2. Required BW PDH – 3.5 MHz/7MHz/14 MHz/28 MHz

APPLICATION1. PDH link was used for Access Network

2. SDH link was used for Backbone Network



TECHNOLOGY

1. Majority of the backhaul link was Hybrid (60%)

2. Hybrid link can deliver TDM and IP traffic in its native platform

3. Both PTP and PMP technologies are used

MODULATION &CAPACITY

1. Maximum Modulation had been increased to 256 QAM

2. Maximum Capacity had been increased to 180 Mbps

3. Adaptive Modulation had been introduced to enhance the reliability

BAMDWIDTH 1.Required BW – 3.5 MHz/7 MHz/14 MHz/28 MHz

APPLICATION

1. Majority of the backbone network had been catered with Fiber ( 60%)

2. High Capacity links with XPIC was used for backbone where fiber network is not presence

3. Low Capacity links with 3.5 MHz/7 MHz/14 MHz were used to backhaul last mile BTS site

4. Backhaul network was developed as L2 Network originated from Regional MPLS nodes.

NEWTECHNOLOGY

1. Adaptive Modulation

2. QoS

3. Link Aggregation

4. Higher Modulation – 256 QAM

5. Synchronous Ethernet



TECHNOLOGY1. All backhaul links are running on IP

2. It is required to used E-Band and V-Band to increase the capacity at dense areas.

MODULATION &CAPACITY

1. Maximum Modulation has been increased to 2048 QAM

2. Maximum Capacity has been increased to 250 Mbps at 28 MHz

3. Maximum capacity can be increased to 500 Mbps if 56 MHz BW is used.

4. Maximum Capacity can be increased to 1Gbps if XPIC and 56 MHz BW is used

5. Maximum Capacity can be increased to 1Gbps if E-Band is used ( 250 MHz Channel)

1.Required BW – 3.5 MHz/7 MHz/14 MHz/28 MHz/56 MHz for Traditional MW band (6- 38 GHZ)

2. Required BW – 250 MHz/500 MHz/1000 MHz/2000 MHz

1. Total backbone and Aggregation requirement is catered with fiber

2. MW backhauling is used in the last mile BTS sites.

3. Maximum 3 MW hop to the closest fiber sites.

4. Backhaul network is running on L3 except the last hop

BAMDWIDTH

APPLICATION

1. Total backbone and Aggregation requirement is catered with fiber

2. MW backhauling is used in the last mile BTS sites.

3. Maximum 3 MW hop to the closest fiber sites.

4. Backhaul network is running on L3 except the last hop

NEWTECHNOLOGY

1. mm Wave ( E-Band / V-Band) communication

2. Enhanced QoS

3. Advance Link Aggregation

4. Higher Modulation – 2048 QAM

5. Carrier Aggregation

6. IEEE 1588 V2 for SynchronizationSATRC Workshop on Spectrum, 16-18 August 2017, Islamabad, Pakistan 19


1. Total link count can be reduced with fiber expansion.2. BW allocated per link should be increased to cater higher capacity demand ( High Dense site required

1Gbps)3. BW allocated per link can be increased without interference due to the reduction of MW link density



eMBB 10G MW

enhanced MobileBroadband

10G Interface

HigherModulation

WiderBandwidth

CarrierAggregation

mm Wave

Automatic ServiceProvisioning

Optimum TransmissionPath

mMTCuRLLC

Cloud MW

Low LatencyMW

Machine to MachineType Communication ultra Reliable Low Latency

Communication

mm Wave

Layer 3 MW 100 uslatency

NetworkSlicing

Optimum TransmissionPath

Network ResourceManagement


CHALLENGERS IN REGULATING BACKHAUL NETWORKS

Interference issues

Difficult to track the main or side lobes for monitoring

Lack of measuring equipment and antennas

Miss alignments of transmission antennas

Lack of channels and higher bandwidths

Higher bandwidths are requested by users to achieve higher speed

Unavailability of low frequencies for long range links

Re-farming lower frequency bands for IMT applications

Shifting existing microwave users to higher bands

Compensations

Disturbance from high rise building in urban areas

Management of huge amount of microwave frequency data and equipment data

Unavailability of Fiber networks in some areas

Interference issues

Difficult to track the main or side lobes for monitoring

Lack of measuring equipment and antennas

Miss alignments of transmission antennas

Lack of channels and higher bandwidths

Higher bandwidths are requested by users to achieve higher speed

Unavailability of low frequencies for long range links

Re-farming lower frequency bands for IMT applications

Shifting existing microwave users to higher bands

Compensations

Disturbance from high rise building in urban areas

Management of huge amount of microwave frequency data and equipment data

Unavailability of Fiber networks in some areas


Thank youMuditha Gunasinghe


Email: [email protected]

Web: www.trc.gov.lk

Thank youMuditha Gunasinghe


Email: [email protected]

Web: www.trc.gov.lk


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