Wireless_backhaul-spectrum_technology_policy.pdf

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 the intermediate 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.

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

2

INTRODUCTION 

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



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



Demand for more available capacity felt more than in the Backhaul.



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



Microwave usage nearly 50% of global backhaul deployments

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

experienced

3

MICROWAVE VS FIBER

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

4

MICROWAVE BACKHAUL 

Microwave backhaul use is higher in emerging market.



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



It has significant spectrum efficiency and backhaul solutions cost 50% less.



Microwave is the predominant form of backhaul for mobile cell sites.



Telecom operators and other users are more like to have their owned 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 fiber tariff in near future.

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

5

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 base station



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 unit and remote radio unit



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

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

6

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 negative impact on the users’ quality of experience (QoE).



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



To adapt to a challenging environment (lamp post, traffic light, etc.), the use of a new form 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/or receiver



Full duplex radios (echo cancellation)



Asymmetrical point-to-point links

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

7

TOPOLOGY OF THE NETWORKS



Point-to-point links 

LoS backhaul 



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

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

8

SELF-BACKHAULING: THE CONCEPT



Self-backhauling defined as when the access (BS-MS) and the backhaul(BS-BS or BS-Network) share the same wireless channel



Sharing options of the wireless channel 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

9

WIRELESS BACKHAUL ADOPTION 

Globally, an increasing percentage of new backhaul investment is in microwave.



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, performance and flexibility.



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

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

10

BACKHAULS IN SRI LANKA 

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



Sri Lanka Telecom (SLT) and Dialog Broadband Network (DBN) have their own fiber as well.



SLT leases their fiber to other operators and other users.



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

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

11

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 



10.5GHz and 28GHz bands are allocated for point-to-multi points applications 



Bandwidths – 3.5/7/14/28/56MHz

70/80GHz band was very recently allocated to high capacity short distance applications 



Bandwidths – 1.75/3.5/7/14/28/56MHz

Bandwidths – 250/500MHz

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

for

Bandwidths – 200/300kHz

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

12

sound

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 by accessing TRCSL database and they should make sure non-interference to existing 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) frequencies for backhaul networks.

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

revenue is collected yearly by

13

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 Frequency Band VLF LF MF HF VHF  VHF  UHF  UHF  SHF  SHF  SHF  EHF I EHF II EHF III EHF IV EHF V EHF VI

Frequency Range

3- 30 kHz 30 -300 kHz 300- 3000 kHz 3 -30 MHz 30 - 100MHz 100- 300 MHz 300 -1000 MHz 1000 -3000 MHz 3-9 GHz 9-20 GHz 20-30 GHz 30-40GHz 40-50 GHz 50-60 GHz 60 -70GHz 70- 90 GHz 90-300 GHz

Fees Payable per kHz of assigned bandwidth of emission(Rs.) 375.00 375.00 375.00 375.00 225.00 375.00 125.00 18.75 10.00 7.50 5.00 2.50 2.00 1.50 1.00 0.50 0.25

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

Power Charges Fees payable per Annum (Rs.) HF and below

VHF Band I & II

UHF Band I & II SHF Band I, II III &EHF Band I,II,II III,IV,V,VI

750.00

3,125.00

2,500.00

1,875.00 3,750.00 5,625.00 5,625.00 5,625.00 9,375.00 9,375.00 12,500.00 18,750.00 50,000.00 93,750.00 187,500.00 Rs.500.00 per additional Watt or part thereof above 1000 Watt

3,750.00 5,625.00 7,500.00 9,375.00 18,750.00 31,250.00 50,000.00 62,500.00 125,000.00 Rs.3,750.00 per additional Watt or part thereof above 100 Watts

3,125.00 5,000.00 5,625.00 7,500.00 12,500.00 18,750.00 37,500.00 Rs.3,750.00 per additional Watt or part thereof above 50 Watts

Transmitter Output Power

) < 1(note

(Watts)

4)

1-5 5-10 10-15 15-20 20-25 25-30 30-50 50-75 75-100 100-150 150-500 500-1000 1000 and above

14

EXAMPLE ON LICENSE FEE CALCULATION 

Consider assignment in 23GHz band for full duplex link with 28MHz bandwidth 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 (per year)

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)

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

15

BACKHAUL NETWORK EVOLUTION IN SRI LANKA

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

16

BACKHAUL NETWORK 2007 1. TDM Technology was used for backhauling 2. Both SDH and PDH were used TECHNOLOGY

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

MODULATION

CAPACITY

BANDWIDTH

APPLICATION

1. 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)

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

1. PDH link was used for Access Network 2. SDH link was used for Backbone Network

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

17

BACKHAUL NETWORK 2012 1. Majority of the backhaul link was Hybrid (60%) TECHNOLOGY

2. Hybrid link can deliver TDM and IP traffic in its native platform 3. Both PTP and PMP technologies are used

MODULATION & CAPACITY

BAMDWIDTH

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

1.Required BW – 3.5 MHz/7 MHz/14 MHz/28 MHz 1. Majority of the backbone network had been catered with Fiber ( 60%)

APPLICATION

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. 1. Adaptive Modulation

NEW TECHNOLOGY

2. QoS 3. Link Aggregation 4. Higher Modulation – 256 QAM 5. Synchronous Ethernet

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

18

BACKHAUL NETWORK 2017 TECHNOLOGY

1. 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. 1. Maximum Modulation has been increased to 2048 QAM

MODULATION & CAPACITY

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)

BAMDWIDTH

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

APPLICATION

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 1. mm Wave ( E-Band / V-Band) communication 2. Enhanced QoS

NEW TECHNOLOGY

3. Advance Link Aggregation 4. Higher Modulation – 2048 QAM 5. Carrier Aggregation 6. IEEE 1588 V2 for Synchronization

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

19

BACKHAUL NETWORK 2018

1. 2. 3.

Total link count can be reduced with fiber expansion. BW allocated per link should be increased to cater higher capacity demand ( High Dense site required 1Gbps) BW allocated per link can be increased without interference due to the reduction of MW link density SATRC Workshop on Spectrum, 16-18 August 2017, Islamabad, Pakistan

20

BACKHAUL NETWORK 2020 enhanced Mobile Broadband eMBB

10G MW

10G Interface Higher Modulation Wider Bandwidth

Automatic Service Provisioning

Carrier Aggregation

Optimum Transmission Path

mm Wave

Network Resource Management uRLLC mMTC

Cloud MW Layer 3 MW

Machine to Machine Type Communication SATRC Workshop on Spectrum, 16-18 August 2017, Islamabad, Pakistan

Low Latency MW 100 us latency

Network Slicing

ultra Reliable Low Latency Communication 21

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

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

22

Thank you Muditha Gunasinghe Deputy Director/Spectrum Management Email: [email protected] Web: www.trc.gov.lk

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

23