2. Small Cell Backhaul = FEAR
street level mounting?
line of sight?
spectrum availability
capacity
costs
vendor hype
LTE requirements?
traffic growth
security, reliability, n
etwork planning
confusing and complicated….
3.
4.
5. NLOS CAPACITY DEGRADES VERY QUICKLY WITH OBSTRUCTIONS
1 mile 5.8 GHz LOS 40 MHz, San Jose CA
130 Mbps
LTE small cell
capacity
requirement
1 mile 5.8 GHz nLOS 40 MHz, San Jose CA
<10 Mbps
LTE small cell
capacity
requirement
6. AND UNLICENSED HAS NOISE…..
-74 dBm
ISM
Source: NTIA Report 00-373 Measured Occupancy of 5850-5925 MHz and Adjacent 5-GHz Spectrum in the United States, 1999.
7. AND CAPACITY DEGRADES EVEN FURTHER WITH INTERFERENCE
1 mile 5.8 GHz LOS 40 MHz, San Jose CA
130 Mbps
1 mile 5.8 GHz nLOS 40 MHz, San Jose CA
<10 Mbps
No Interference
70 Mbps
-74 dBm
interferer signal
LTE small cell
capacity
requirement
No Interference
N/A
LTE small cell
capacity
requirement
-74 dBm
interferer signal
10. POSSIBLE SPECTRUM FOR BACKHAUL
32,000 MHz
830 MHz
BACKHAUL SUB-6GHZ
TOTAL MICROWAVE + MILLIMETERWAVE
11. LATENCY CONSIDERATIONS
Radio Type
Sub 6GHz PTmP TDD
4-15ms
Sub 6GHz PtP TDD
3ms
PTP Microwave FDD
11
Typical
Latency
(one way)
0.3 - 0.6ms
LTE Latency
Requirement:
20ms one
way, multihop/total
IEEE
1588v2
SyncE
No
Depends on number
hops
No
No
No
No
Yes
Yes
Yes
12. Sub 6GHz solutions should be seen as last resort option
for LTE small cell backhaul today
New innovations talked about (largely still long ways off)
13.
14. REPRESENTATIVE POLE FOR ANALYSIS
Pole Characteristics
Structure: monotubular aluminum tower with
x
cantilever arm
z
Dimensions:
– Pole height:10.67 m
– Diameters: bottom 25 cm, top 15 cm
– Cantilever arm:
3.66 m spread, 1.52 m rise
Accelerometer
positions
15. MAXIMUM DISTANCE (99.99%) AND WIND SWAY
Max
Max
Distance Distance
Pole to Pole
Deployment
San Jose
Miami
Wind is just
another factor
that needs to be
incorporated into
the path
planning
(rain, capacity, re
liability, etc)
Frequency Band (GHz)
Frequency Range (GHz)
Antenna Gain (dBi)
Antenna 3dB beamwidth (°)
Antenna Size (m)
Max Radio Power (dbm)
Channel Size (MHz)
Maximum FCC 3dB Beamwidth (°)
Minimum FCC Antenna Gain (dBm)
FCC Max EIRP (dBm)
Target Availability (%)
QPSK Max Distance / Throughput
16QAM Max Distance / Throughput
64QAM Max Distance / Throughput
QPSK Max Distance / Throughput
16QAM Max Distance / Throughput
64QAM Max Distance / Throughput
Maximum wind speed: 11 MPH
Maximum wind speed: 22 MPH
Maximum wind speed: 34 MPH
Maximum wind speed: 45 MPH
18
17.700–19.700
33.5
2.2
<0.3
51.5
80 MHz
3.3
33.5
85
99.99
4.3 Mi / 90 Mbps
3.1 Mi / 182 Mbps
2.6 Mi / 269 Mbps
11 Mi / 90 Mbps
7.5 Mi / 182 Mbps
6 Mi / 269 Mbps
0.2°
0.44°
0.52°
1.28°
23
21.2-23.6
30.5
3.3
<0.3
34.5
50 MHz
4.5
30.5
65
99.99
2.3 Mi / 74 Mbps
1.7 Mi / 148 Mbps
1.3 Mi / 233 Mbps
5.5 Mi / 74 Mbps
4 Mi / 148 Mbps
2.9 Mi / 233 Mbps
0.2°
0.44°
0.52°
1.28°
70/80
71-80
43
1.2
<0.3
42
1000 MHz
1.2
43
85
99.99
0.9 Mi / 360 Mbps
0.8 Mi / 720 Mbps
0.6 Mi / 980 Mbps
1.8 Mi / 360 Mbps
1.5 Mi / 720 Mbps
1.1 Mi / 980 Mbps
0.2°
0.44°
0.52°
1.28°
Utility and standard
compliant short
light poles are less
likely to sway and
should be preferred
for SC
Pole to pole for
gusts > 45mph on
Eband links is the
only scenario
where wind-related
outages might
occur (above
10dB)
16. 80GHZ: THE DIMINISHING ALIGNMENT/INSTALLATION CHALLENGE
1990’s
poor training skills
large transceiver/enclosure
heavy
separate antenna
inflexible
difficult to manipulate
slow
coarse alignment tools
½ day to install
2012
high quality training/skills
small transceiver/enclosure
light
integrated antenna
flexible
user friendly
fast
highly accurate
alignment tools
½ hour to install
17.
18. TIGHT INTEGRATION OF PICOCELL AND BACKHAUL UNLIKELY
LOOSE INTEGRATION POSSIBLE
(‘AFTER MARKET’ PACKAGING)
SMALL CELL
24. Construction is Key LTE
Challenge Today…
will be much worse w/ small cells
so, its not all about technology widgets…
25. WHICH MEANS
FUNDAMENTAL INNOVATIONS WILL BE REQUIRED IN
FOUNDATIONAL MICROWAVE TECHNOLOGY…
all in one tiny box...
including antenna!
25
AVIAT NETWORKS
FEBRUARY 2012
|
26. TO ACHIEVE SMALL CELL VISION,
we need
to pay
attention
to what’s
important…
Welcome to ATS, Live from SC, IntroductionsHousekeeping:- Ask questions in Q&A function (mute) – we’ll try and get to themChat function to administratorMarketing@aviatnet.comNot sales pitches – technology overviewsTopic: Small cell backhaulFocus: outdoor mounted pico and micro cells and specifically on backhaul issues regarding wireless BH solutionsFocus: LTE – NA audience
There is a ton of talk about small cell now and the one common theme is there’s lots of uncertainty… even for basic questions like is this evolution even going to happen… we’ve heard everything from small cells are the future, to the business case for small cells is not clear. One thing is for sure, small cells are all the rage right now and from a backhaul standpoint, small cells really change the BH paradigmThere are a lot of factors contributing to the confusion – listed on this slideOne thing is for sure is: if this evolution happens, there will beMore sites - higher cost, - more complexityDifferent types of sites - new technologies
What’s a myth? Something that is based on passed down via stories and beliefs and is generally not testable. Science on the other hand is based on cumulative, frequently updated knowledge, supported by proven facts and repeatedly testable processes.Like common myths there are perceptions about small cell that are based on misinformation—heresay—even intentional deception. We're here to debunk those myths and provide you with science and facts regarding Small Cell backhaul issuesThe rest of this presentation will be structured as kind of a myth busters – and we have 5 of them
Is that sasquatch lives!!! Hardly… because despite a number of claimed sightings all across the US, we at Aviat are pretty certain that based on science, he is a fable.We hear all the time that i’m not going to have LOS to my small cell therefore I will need a NLOS solutionThus, solutions deployed in freq bands of 6GHz and below are best for SC BHWe don’t believe this to be based on science – this needs a reality check with some analysis and dataLets take a look
For instance, 3.5G band has 20MHz channel possibilities internationally
Spectrum better used for access spectrum
the developments in 2.3GHz WCS (ATT wanting to move this to access spectrum) is sign of things to come and supports your point of lack of spectrum <6GHz and every bit of it will be needed for RAN/access
Backhaul requirements are more commonly in the range of <8 to <16 ppb in terms of clock recover accuracy – many TDD systems are in the range of 50pbb at bestOne way delay is not as much of a factor for 1588v2 as delay variation, so how well their system will perform will more depend on their dejitterizer capabilities than their latency spec.
Because of capacity and synchronization concerns, Large antenna arrays for mimo implementationsLTE based system on chip solutions (need to add 256qam)
First mentioned by the ancient greeks, The unicorn is a legendary animal from European folklore that resembles a white horse with a large, spiraling horn projecting from its forehead, and sometimes a goat's beard and cloven hooves. Again… folklore.Similarly, I hear it all the time that PTP (MM Wave) wont work on a pole (primarily b/c of sway and twist and wind, but also because of alignment challenges) – narrow beams
Comments: Sway was taken for worst case scenario in Y-Z plane. Maximum distance was calculated using Maximum FCC antenna beam width and minimum antenna gain and typical radio specifications. Outdoor light poles are designed for maximum gust velocities defined in 50 years mean maps like AASHTO (see backup slides) with a minimum wind load of 70 MHP, maximum EPA and weight loading. Sway does not necessarily increase with wind speed as natural turbulence of the air stream at higher speeds. TIA-222-F defines a maximum sway and twist angle based on the antenna beam width calculations in blue show the maximum distance if the link would work continuously at this angle as a point of reference to the pole sway angles. Maximum distance calculations for a fixed availability of 99.99% were performed for San Jose CA and Miami FL based on environmental conditions for these two cities considering rain and multi-path. ITU-530-11 was used with plain terrain. Horizontal antenna polarization was assumed. Pole to Building scenario assumes that the building is static and all sway is due to pole movement. Pole to pole scenario assumes worst case scenario were both poles sway simultaneously resulting in a doubling of sway angle. This scenario is extremely unlikely as both poles would have to sway in synchronization. In the pole to pole deployment with a wind speed of 45 MHP at 70/80 GHz pole sway is above antenna beam width resulting in antenna attenuations above 10dB.
Specificallyconcernherewith the higher bands (again 80GHz) wherebeams are verynarrow and the mostproblematicwhenalignmentisconcerned1990’sCoarsealignmenttoolswere of the Digital voltmeter type (RSSI) and with a fairlywidetolerance; not great for a narrowbeam. 2000’sNowthereis a combination of- much more accurate RSSI readings via laptop and voltmeteraudio signal athighsampling rate to providehighlyaccuratealignment assistance/tracing andoptical alignment tool – example – can be attached to radio for accurate alignment – right angle versions can be used for wall mount much more flexible mounts and smallerlightertransceiversthat are easier to manipulate/alignespecially if they have an integratedantennaFuture- the potential for electromechanical self alignmentutilizinguber-small flat antennas (cost)- thereis scope for innovation whenitcomes to alignment techniques and we’reinvestigating a potentiallyveryfast, user friendly, non opticalalignment technique (currentlyunder patent assessment)
Anyone ever been to disney?Did your dreams come true?Not likely.Similarly I hear this one a lot too – that BH needs to be integrated with the picocell
doesn’t make sense for ran vendors to build bh into their solutions since it drives up cost and complexity and number of product variants they would need to support?count possible product variants and estimated costs to add each one…Utilities want something standardized since they want to make sure structure and engineering on the poles are soundThey also are likely going to make sure installers are well trained to work on poles, etcStandardized package will be required
FCC is quite flexible in these bands: you can back off the power, no EIRP limitationsHigh volumes of PTP bands – lower costsPTMP shares spectrum – lower capacity70/80: 38dBi gain, 1.2degbeamwidthSmaller hops: equipment can be designed with lower power, thus smaller, etcVerizon (based on Napa trial) – SC distances trialed were between 0.3 to 0.7 KMVerizon (from Exalt preso) – NLOS BH from 1.5-2.0 KM Vodafone UK (Presented at SC World Summit)- Busy areas require 50m radius microcells, Microcell range limited to 150m due to building loss and corner loss. Busiest 200x200m area requires 6 microcells plus 3 carrier picocells/public femto cells Everything Everywhere (based on customer input): From 50m to 400m
We all know who this is right?What could Dwight Eisenhower possibly have in common with LTE?Well, he is probably best known for commandingour troops in WW2 and it was when the Allies broke through the Western Wall he noticed something that would change the history of this country – he saw Germany's sprawling autobahn network and realizedwhat a modern army could do with an infrastructure capable of accommodating itWhen he eventually became president,IKE initiated the Federal-Aid Highway Act of 1956: Creating the Eisenhower Interstate SystemOne of the biggest construction projects in the history of the country - 41,000 miles of freeway to every nook and cranny of the countryThat’s exactly what LTE is – a massive construction project. New backhaul (digital highways) will have to be put into 300,000 cellsites in the USWith the IHS, it wasn’t the size of the highways (2 or 3 lanes) that that meant 35 years of work, it was all that goes along with building a road of any size – and the number of them - in a tight timeframe. Similarly, LTE BHis actually lessabout the capacity or the size of the digital highway(both microwave and fiber both exceed the capacity requirement), but more about getting a backhaul solution deployed in the first in place – since its urgent and expensive but also very complicated
So we see the real LTE challenge is not being only about capacity, but mostly construction or perhaps more accurately implementation.It’s the site surveys, frequency coordination, the engineering, planning, and installation, troubleshooting when something goes wrong, etc, etc. No two sites are the same, and 2/3G not going away, and there’s no more people to do all this withWhat we’re focused on as a company is making sure MW meets the capacity needs of LTE, and more importantly figuring out ways we can ease the implementation pain.Today's presentation: 2 things:Capacity: and features that exist to meet the LTE capacity need – our recommendations for which ones make senseConstruction:and some of the ways we can help ease the pain and simplify your life (both from features on the radio standpoint, and services standpoint)Business Case cannothold water if installation is longer than 45mm (presented by the NGMN @ the Packet MW conf in London)
Often called “The seventies answer to George Jetson's mode of transportation” – the AMC pacer is one of the most interesting cars… Anyone ever own one?"The Flying Fishbowl”- Great wheels, snazzy paint scheme, white leather seats, rear roof spoiler, lots of windows, cupholders…..a lot of stuff, but one of the worst cars of all time – it didn’t work(didn’t work, wasn’t reliable and wasn’t practical)FOCUS ON WHAT”S IMPORTANTWhat’s important?Easing construction Pain – especially with small cells !!!Delivering new innovations to reduce costs, make microwave easier to deploy, and integrated into the rest of the networkStand-alone LOS-based solutions emerging as most viable SC BH optionMaking them easier to deploy will be key