iot m2m case study analysis

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IoT M2M Case study Real network projects

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Case study 1

LTE TDD RURAL COVERAGE for M2M services

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Project scenario

Provide LTE coverage for M2M forest surveillance over mountainous

rural areas

Technical project requests:

1. Check for high temperature/gas/fire alerts

2. Check for video confirmations on alerting

3. All in one board architecture

4. Autonomous power – solar or PoE

5. Connect through LTE to a main server

6. Use C-RAN connectivity to minimize implementation

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Project scenario


rural areas


1. Check for high temperature/gas/fire alerts

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Project scenario


rural areas


2. check for video confirmations on alerting

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Project scenario


rural areas


3. All in one board architecture

The solution

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Project scenario


rural areas


4. Autonomous plug and play

Sensor probes can be easily attached

by just screwing them into the bottom

sockets

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Project scenario


rural areas


4. Autonomous power – solar or PoE

Sensor probes can be easily attached

by just screwing them into the bottom

sockets

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Project scenario


rural areas


5. Connect through LTE to a main server

The Sensor data gathered by the Waspmote Plug & Sense! nodes is sent to the Cloud

by Meshlium it is a Gateway router specially designed to connect Waspmote sensor

networks to the Internet via Ethernet, WiFi and 3G interfaces

Meshlium

LoRAWAN

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Project scenario


rural areas


5. Connect through LTE (3.6 GHz) to a main server

The Sensor data gathered by the Waspmote Plug & Sense! nodes is sent to the Cloud

by Meshlium it is a Gateway router specially designed to connect Waspmote sensor

networks to the Internet via Ethernet, WiFi and 3G interfaces

Meshlium

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Project scenarioTechnical project requests:


Forest shelter – local aggregator

Indoor shelter VoIP,

data/internet and O&M

services

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Project scenario



Why LTE ???

Among proposed 3GPP technologies with non-dominant standardized

solution so the most popular due to its cost effectiveness and simplicity

on network implementation is the LTE-A.

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Project scenario



Why LTE 3.6 GHz ??

In Greece LTE 3,6 GHz is an unused band

Project has been supported by government, through EU funding.

Greek frequency authorities (EETT) has allocated the 3.6 GHz band free

of charge to the Rural project since it is unused so far

Two channel bandwidths have been reserved:

- 3.6 GHz 30 MHz channel bandwidth

- 3.8 GHz 30 MHz channel bandwidth

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Project scenario



Why LTE 3.6 GHz TDD???

In Greece LTE 3.6 GHz TDD is an unused band, leaving other TDD sub-

bands available for other future services

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Project scenario



Why LTE C-RAN ???

Most world dominant vendors are proposing the LTE-A network

architecture and functionality to support the C-RAN approach and to

migrate towards 5G.

C-RAN concept is proposed to be based on a centralized baseband

processing pool equipment serving a number of clustered distributed

radio access nodes (RRUs).

Furthermore in legacy operator networks such as LTE-A and

Heterogeneous Networks, where coordinated functionality and real-time

processing is essential to performance interference as well as mobility

and synchronization improvements, the cloud RAN approach is easily

accommodated.

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Project scenario



Why LTE C-RAN ???

cell planning principles are quite similar to LTE-A with extra restrictions

and demands adapting to the specific traffic and service.

Ericsson & Huawei have lately (early 2016) proposed a combination of

powerful software features to combine cloud RAN with LTE-A technology

and deliver extreme application coverage with huge peak cell

throughputs over existing 4G operator infrastructures, in an effort

towards 5G networks aligned with 3GPP and 5GPPP standards and

proposals.

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The project architecture

C-RAN architecture use Huawei eA360 Customer Premise

Equipment (CPE) at 3.6-3.8 GHz

Meshlium

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C-RAN architecture use Huawei DBS3900 eNodeB technology with

RRU3232 at 3.6-3.8 GHz

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RRU3232 at 3.6-3.8 GHz

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BBU3232 at 3.6-3.8 GHz

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In such architectures a large number of remote Remote Radio

Handlers/Remote Radio Units (RRH/RRU) are deployed over a large

geographical area, all connected over front haul fibre links (dark fibre

links), towards a centralized pool Base Band Unit (BBU) on cloud server

with typical cell coverage ranges of 15-20 Km over fibre links for LTE-A

solutions.

It is widely accepted that using RRH/RRU distributed units over radio

interface introduces advanced technologies over radio access network,

moving processing load functions to the cell edge devices (Mobile Edge

Computing solutions) and exploiting IP/ethernet with emphasis to MPLS

over optical network technology for the RAN transmission and backhaul

network topology.

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Such a design facilitates any kind of traffic over a well-planned LTE-A

network including traditional IP subscriber web traffic, cloud services,

sensor based traffic as well as generic IoT services of any kind.

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C-RAN settings activate TTI bundling

What is TTI bundling?

TTI bundling is signaled by rrcConnectionReconfigution.

You can see in 3GPP TS36.331 6.3.2. Key word is ttiBundling and MAC-

MainConfig

There are thresholds defined at the eNB,

This trigger condition shall be checked with every UL transmission of the

UEs and if the trigger condition is fulfilled, the eNB shall inititate the

process to start TTI bundling for the UE.

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This feature is activated in eNB as RRCReconfigurationRequest during

the intial PDP context for default bearer established.

Again device must be supported as device capabilities message. After

that UL will be automatically group every 4 TTI.

Re-transmittion of NACK is corrected at 9 sub-frames later. Basically

when device is moved around at cell edge the errors of PUSCH is

overwhelming therefore TTI bundling is reduced the overhead and

resources of HARQ - MAC layer.

Note: in Rel 10 it might not be allowed to enable both Semi-Persistent

Scheduling and TTI bundling at the same time.

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Like If the UE has gone in bad radio condition or cell edge where the

Current Modulation and coding scheme has gone below or equal to the

threshold defined for triggerring the TTI bundling.

If TTI bundling measurements are ongoing and the percentage of

NACKed transmissions is greater than Bler threshold for TTI bundling.

Based on these criterion, eNB can trigger the TTI bundling for the UE.

Similarly if the UE moves back again to good radio condition the eNB will

ask the TTI bundlng to be turned off.

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Check also

beside the options present above one could consider using additional

triggers (at the eNB side to start RRC reconfig).

For example:

1. PHR (power headroom) report in addition to measured UE power in

the up-link.

2. Using known eNB tx power and maximal UE power to configure A1

and A2 measurement event (36.331 A1/A2=Serving becomes

better/worst than threshold).

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Remarks

1. improving the data part (PUSCH) by TTI bundling is not enough, one

need to look on the control channel send over PUCCH (e.g. use

repetition).

2.

2. The implications on the MAC design are all by trivial, for example

how the MAC scheduler works in both UL and DL (if PUCCH

repetition is used) when combining UEs with bundling and few w/o.

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C-RAN settings RRC connected users ???

There is RRC connected user license limit provided by vendor. By

default, this is 60 (as per my knowledge and experience).

As users increase in network, you need to buy license allowing more

users from vendor.

If you guide me which vendor you are working ,I might be able to send

you the license parameter to check.

Secondly, there is product capacity provided by the

Again this can be identified if product version is known.

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C-RAN settings RRC connected users ???

Do not confuse it with applicability while considering 1 ms TTI and 20

MHz BW.

There is difference between theoretical and practical limitations. Specific

equipment has its limitation in processing the load.

This is the reason you are observing challenge in understanding this.

RRC connected user capacity is provided at eNB level.

This is the number of UEs in connected mode at an instance.

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LoRAWAN RAN planning considerations

LoRAWAN technical specs.

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Our project scenario

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Our surveillance scenario

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C-RAN Design considerations

SINR considerations: The major concern is related to the uplink cell

planning & optimization issues in such a way to guarantee adequate

SINR for accepted service accessibility as well as integrity

(throughput) performance.

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SINR considerations

assure the signal-to-noise ration over the uplink receiving levels so that uplink

RRH = arg

uplink

t et on

RRH/RRU unit, otherwise several severe side effects might take place

Suppose that CPE outdoor unit transmits on power level , arg

UE

o t etP and the receiving RRH unit

receives a signal strength RRHSE = ,min

UL

RP , then RRH receiving unit will be able to successfully

decode the received signal under a noisy and interference channel link.

Receiving sensitivity RRHSE

is defined as the minimum receiving signal levelmin

UL

RP ,

depending on the requested CPE outdoor unit transmitted power , arg

UE

o t etP and is given by the

following formula:

, arg

min

( ) ( )UE T R

o t et o o o oUL

R RRH

pathloss j LNA f C

P G GP SE

L L L L L

where jL are the jumper losses on RRH antenna unit, LNAL is the LNA losses if

used, fL are the waveguide (feeder) losses, CL are the feeder connector losses

over LNA.

(1)

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SINR considerations

The ideal condition for successful decoding on the receiving RRH unit is:

1R feeder

f pathlossLNA

RRH t BW f

LNA

N LSE N RB N

G

Check next slide

(2)

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C-RAN Design considerations SINR considerations

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Substituting (2) on (1) will contribute into the sufficient uplink sensitivity condition on RRH receiving unit

, arg1( ) ( )

R feederUE T Rf pathlosso t et o o o o LNA

RRH t BW f

pathloss j LNA f C LNA

N LP G GSE N RB N

L L L L L G

, arg

1

( ) ( )

R feeder

f pathlossLNA

t BW f pathloss j LNA f C

LNAUE

o t et T R

o o o o

N LN RB N L L L L L

GP

G G

(3)

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LTE-A for C-RAN has a superior power control algorithm to compensate for adequate power for

the received level of however there should be further considerations regarding some extra

restrictions since maintaining always condition on equation (3) is not always feasible.

This is because CPE outdoor unit has predefined hardware restrictions on the maximum allowed

transmitted power

Moreover than that there is a maximum allowed uplink power threshold posed by RAN

optimizer to mitigate and keep inter-cell interference as low as possible (an example might be the

Ericsson parameter pMaxServingCell).

Considering these extra restrictions equation (3) is rewritten as follows:

, arg

UE

o t etP

0

UEP

max,

UE

ulP

max, , arg

min

min ,min , ( ) ( )UE UE UE T R

o ul o t et o o o oUL

R RRH

pathloss j LNA f C

P P P G GP SE

L L L L L

(4)

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The major problem that RAN designers might face on LTE-A C-RAN planning for IoT

sensor applications is that quite often, due to load (inter-cell interference in the area),

LTE-A CPE outdoor unit might easily be saturated on uplink transmitted power.

This means that the power control algorithm might request (under loaded conditions) CPE

outdoor unit to increase uplink transmitted power , to fulfill the RRH/RRU received

SINR or power level, however the CPE outdoor unit might fail (saturates) since:, arg 0,

UE req

o t et uplinkP P

- Requested CPE outdoor unit transmitted power , arg max,

UE UE

o t et ulP P , hence saturates

since max, , argmin ,UE UE

ul o t etP P = max,

UE

ulP , that is restricted from configured parameter (i.e.

Ericsson parameter pMaxServingCell ).

- Requested CPE outdoor unit transmitted power , arg max,

UE UE

o t et ulP P hence there is

enough power since max, , argmin ,UE UE

ul o t etP P = , arg

UE

o t etP , but on the same time

, arg max,

UE UE UE

o o t et ulP P P as a result fails (saturates) to respond to that power

request because of hardware circuitry restrictions since

max, , argmin ,min ,UE UE UE

o ul o t etP P P = , argmin ,UE UE

o o t etP P = UE

oP saturation due to

power CPE outdoor specifications.

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The major problem that RAN designers might face on LTE-A C-RAN planning for IoT

sensor applications is that quite often, due to load (inter-cell interference in the area),

LTE-A CPE outdoor unit might easily be saturated on uplink transmitted power.

Considering both previous conditions it holds that:

Requested ( , arg

UE

o t etP UE

oP ) ( , arg

UE

o t etP max,

UE

ulP )

And as a consequence always:

1R feeder

f pathlossLNA

eNodeB t BW f

LNA

N LSE N RB N

G

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Planning Conclusions:

1st Conclusion: C-RAN designers, considering the necessary CPE outdoor unit uplink

connectivity, have to ensure that previous saturation conditions should never happen!!!

2nd Conclusion: Considering all design restrictions as well as the RRH/RRU sensitivity conditions:

max, , argmin ,min , ( ) ( ) 1UE UE UE T R R feeder

o ul o t et o o o o f pathlossLNA

eNodeB t BW f


P P P G G N LSE N RB N

L L L L L G

max, , arg

1

min ,min ,( ) ( )

R feeder

f pathlossLNA


LNAUE UE UE

o ul o t et T R

o o o o

N LN RB N L L L L L

GP P P

G G

, arg

1

( ) ( )

R feeder

f pathlossLNA


LNAUE

o t et T R

o o o o

N LN RB N L L L L L

GP

G G

(5)

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2nd Conclusion: Considering all design restrictions as well as the RRH/RRU sensitivity conditions:

Considering strict condition for max, , argmin ,min ,UE UE UE

o ul o t etP P P = UE

oP , r R :

- Initial setting of maximum power max,

UE

ulP parameter configuration on every cell

coverage area r R (i.e. Ericsson parameter pMaxServingCell) shall be such that

max,

UE UE

ul oP P max, , argmin ,UE UE

ul o t etP P UE

oP r R .

Simultaneous power control parameter configuration, combined with maximum

geographical coverage R should be such that: , arg max,

UE UE UE

o t et ul oP P P r R

max, , argmin ,UE UE

ul o t etP P = , arg

UE

o t etP r R max, , argmin ,min ,UE UE UE

o ul o t etP P P = UE

oP r R

ensuring condition , arg

UE

o t etP r R .

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3nd Conclusion: A good C-RAN proposal is to use a design margin , so that any Noise and

Interference peaks will be over-dimensioned and absorbed on initial design.arg 3mP dB

max, , arg

arg

min ,min , ( ) ( ) 1UE UE UE T R R feeder

o ul o t et o o o o f pathlossLNA

eNodeB t BW f m


P P P G G N LSE N RB N P

L L L L L G

arg

max, , arg

1

min ,min ,( ) ( )

R feeder

f pathlossLNA

t BW f m pathloss j LNA f C

LNAUE UE UE

o ul o t et T R

o o o o

N LN RB N P L L L L L

GP P P

G G

arg

, arg

1

Power Control decision ( ) ( )

R feeder

f pathlossLNA

t BW f m pathloss j LNA f C

LNAUE

o t et T R

o o o o

N LN RB N P L L L L L

GP

G G

(6)

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C-RAN Design considerations Accessibility Considerations: Cell selection in idle mode (camping) is also

crucial for the C-RAN CPE outdoor unit, since wrong cell camping will lead to

RRH/RRU sensitivity condition failure!!!

The answer is to follow always the 3GPP specifications (i.e. 3GPP TS 36.304)

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C-RAN Design considerations Accessibility Considerations:

According to 3GPP TS 36.304 cell camping is validated following the recommendation:

min min 0rxlev rxlevmeas rxlev rxlev offset compensationS Q Q Q P

Where rxlevmeasQ is the real CPE outdoor unit measured downlink RRH transmitted power over

the reference signals RS (RSRP signal strength measurement, minrxlevQ is a configurable cell

parameter broadcasted over BCCH channel on the downlink and minrxlev offsetQ is an offset

configuranle parameter for fine tuning purposes.

compensationP is a power configurable parameter and according to 3GPP recommendations

compensationP = max ,0EMAX UMAXP P .

EMAXP is based on 3GPP EMAXP = max,

UE

ulP and UMAXP is according to 3GPP UMAXP = UE

oP .

(7)

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C-RAN Design considerations Accessibility Considerations:

Substituting into (7) we could get the updated cell camping suitability condition:

min min max,max ,0UE UE

rxlev rxlevmeas rxlev rxlev offset ul oS Q Q Q P P

Following nominal cell planning and considering the LTE-A outdoor unit cell selection to guarantee the equation (5) sensitivity conditions, cell planners should always select camping parameters so that:

- In every geographical cell coverage area r R condition to be fulfilled is

min minrxlev rxlev offsetQ Q rxlevS r R , so that always 0rxlevS

- In every geographical cell coverage area r R condition to be fulfilled is max,

UE UE

ul oP P

r R , so that always max,max ,0UE UE

ul oP P = 0 r R 0rxlevS , r R

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Throughput considerations.

Throughput depends on SINR, pathloss as well as LoS conditions

Follow excel file, provided by instructor, for further analysis

iot m2m case study analysis

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