This paper presents an exhaustive study on the use of one-relay and two-relay cooperative communication schemes and 2-hop communication scheme for improving the energy efficiency and reliability of ultra-wideband based wireless body area networks (UWB WBANs). Various investigations have been performed to study the impact of the parameters like packet size, hop distance, transmit power and channel error rate on the energy efficiency and reliability. An optimal packet size is obtained for the maximization of energy efficiency for both on-body communication and in-body communication. The analytical and simulation results show enhanced reliability with cooperative communication than direct communication and 2-hop communication, for all values of source to destination distances. The results also depict a threshold behaviour for energy efficiency which separates the hoplength for direct transmission from the hoplength where cooperation and 2-hop communication will be useful. The simulation results reveal that if the channel conditions are poor, when the source to destination distance is larger than the threshold value, 2-hop communication gives higher energy efficiency compared with direct and cooperative communications.

1. See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/332407586
ENERGY EFFICIENT IR-UWB WBAN BASED ON THE IEEE
802.15.6 STANDARD
Presentation · April 2019
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ULTRA WIDE BAND WIRELESS BODY AREA NETWORKS View project
Energy efficient communication in IEEE 802.15.6 UWB WBAN View project
Aravind M T
National Institute of Technology Calicut
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2. ENERGY EFFICIENT IR-UWB WBAN BASED ON THE IEEE
802.15.6 STANDARD
Aravind M T
Guide: Lillykutty Jacob,
Professor NIT Calicut
4 May 2018
4 May 2018 1 / 61

3. Overview
1 Introduction
2 Literature survey
3 work done
4 Packet success probability
5 Energy Consumption Analysis
6 Optimal packet size
7 Simulation results
8 Conclusion
9 References
4 May 2018 2 / 61

4. Introduction
Introduction
What is BAN. . . ???
Definition by IEEE 802.15.6:
“A communication standard optimized for low power devices for their operation on,
in or around the human body (but not limited to humans) to serve a wide variety of
applications including medical, consumer electronics or personal entertainment and
other.”
4 May 2018 3 / 61

5. What is Ultra Wide Band ?
4 May 2018 4 / 61

6. 4 May 2018 5 / 61

7. UWB Properties
Highly Secured
Non-interfering to each other communication systems
Appears like noise for other systems
Both Line of Sight and non-Line of Sight operation
High multipath immunity
Low cost, low power, nearly all-digital and single chip architecture
Large channel capacity
4 May 2018 6 / 61

8. Cooperative communication
efficient strategy for providing spatial diversity in wireless fading channels .
can improve energy efficiency as well
the source transmits information to the destination not only through direct link
but also through the use of relays
could be single-relay based or multiple-relay based
relay selection might be opportunistic or deterministic
relaying strategy can be fixed, selective or incremental
4 May 2018 7 / 61

9. 1-Relay cooperative communication
aims to save channel resource compared to cooperative relaying
ensures that relaying process adapts to channel conditions
ack feedback from destination indicates successful direct transmission
nack feedback indicates need for relaying
4 May 2018 8 / 61

10. 2-Relay cooperative communication
two potential relays (r1 and r2) are available to help a given source.
4 May 2018 9 / 61

11. 2-Hop communication
source node sends packet to the relay node in the 1st time slot → relay node
forwards that packet to the destination node in the 2nd time slot.
4 May 2018 10 / 61

12. Literature survey
Literature Survey
Mohammad Sadegh Mohammadi, in [1] give a detailed literature about
Optimal Frame Length to Maximize Energy Efficiency in IEEE 802.15.6 UWB
BAN
Packet success rate of both the PHY modes of the standard are derived.
1
Mohammad Sadegh Mohammadi, Qi Zhang, ErykDutkiewicz, and Xiaojing Huang, ““Optimal Frame Length
to Maximize Energy Efficiency in IEEE 802.15.6 IR-UWB Body Area Networks ”, IEEE wireless communications
letters , vol. 3, n o . 4,pp:397-400 august 2014
4 May 2018 11 / 61

13. Literature survey
In [2],Deepak K S, discussed about .
The energy efficiency analysis of incremental relay based cooperative
communication in WBANs based on narrow band physical layer is presented.
The packet size optimization of direct as well as cooperative communication
was proposed.
In [3] authors proposed a relay selection procedure for energy efficient
cooperative communication .
2
K. Deepak and A. Babu, “Improving energy efficiency of incremental relay based cooperative communications
in wireless body area networks ”, International Journal of Communication Systems, 2013.
3
D. Jie, E. Dutkiewicz, X. Huang and G. Fang., “Energy-efficient cooperative relay selection for UWB based
body area networks ”, IEEE International Conference in Ultra-Wideband(ICUWB) 2013, pp.97-102.
4 May 2018 12 / 61

14. Literature survey
Selection of the most energy efficient modulation and FEC scheme.
→In [4], M.C.Domingo,mainly emphasizes the selection of an optimal packet size.
Automatic Repeat Request (ARQ) scheme, forward error correction (FEC) block
codes, and FEC convolutional codes were analyzed.
The hop-Length extension scheme is also applied to improve the metric with FEC
block codes.
5
M. C. Domingo““ Packet Size Optimization for Improving the Energy Efficiency in Body Sensor Networks”,
ETRI Journal, vol. 33, no. 3, pp. 299-309, Jun 2011.
4 May 2018 13 / 61

15. Literature survey
In[5] the authors discuss about,
energy efficiency models in 1-hop, 2-hop and cooperative communications in
multipath fading channel.
optimal packet size to achieve the maximum energy efficiency.
A cross layer approach for optimizing energy efficiency of impulse radio (IR)
UWB that use non-coherent energy detection receiver and on-off keying
modulation is utilized in [6] and [7].
5
Nattakorn Promwongsa,TeerapatSanguankotchakorn“Packet Size Optimization for Energy-Efficient 2-hop in
Multipath Fading for WBAN., The 22nd Asia-Pacific Conference on Communications (APCC2016).
6
H. Karvonen, J. Iinatti, and M. Hamalainen, “Energy efficiency optimization for ir-uwb wban based on the
ieee 802.15. 6 standard,” in Proceedings of the International Conference on Body Area Networks. ICST (Institute
for Computer Sciences, Social-Informatics and Telecommunications Engineering), 2013, pp. 575–580.
7
H. Karvonen, J.Iinatti, and M. Hamalainen, “A cross-layer energy efficiency optimization model for wban
using ir-uwb transceivers,” Telecommunication Systems, pp. 1–13, 2014.
4 May 2018 14 / 61

16. Literature survey
Packet size optimization for a two hop data communication system composed of
a WBAN and a WiFi network is considered in [8].
Packet size optimization for congestion control in pervasive healthcare
monitoring is considered in [9].
8
2Y. Li, X. Qi, Z. Ren, G. Zhou, D. Xiao, and S. Deng, 1–8.“Energy modeling and optimization through joint
packet size analysis of bsn and wifi networks., in Performance Computing and Communications Conference
(IPCCC), 2011 IEEE 30th International. IEEE, 2011, pp.
9
N. Yaakob and I. Khalil, “Packet size optimization for congestion control in pervasive healthcare monitoring,”
in Information Technology and Applications in Biomedicine (ITAB), 2010 10th IEEE International Conference on.
IEEE, 2010, pp. 1–4.
4 May 2018 15 / 61

17. Literature survey
Problem Definition I
We conclude the following from the detailed literature survey on different
communication scheme in UWB based WBAN:
There is need to investigate the energy efficiency and reliability of UWB
WBANs when different communication schemes are used.
Such a study is very crucial towards energy aware WBAN design.
The project aims at the following
Investigate direct,2-hop and cooperative communication technique involving
decode-and-forward relays with realistic channel models applicable for UWB based
WBANs.
Develop models for energy efficiency and link reliability for various strategies
under consideration.
Focus on energy consumption and reliability of WBANs considering IEEE 802.15.6
specifications and realistic in-body and on-body channel models.
Investigate optimal packet size that maximizes energy efficiency of direct,2-hop
and cooperative communication schemes in WBANs with UWB PHY layer.
4 May 2018 16 / 61

18. work done
SYSTEM MODEL
A set of wireless sensor nodes which communicate with the master hub node is
being assumed .
The nodes transmit in the orthogonal time slots.
Standard specifies two modes for IR-UWB PHY:
1 Default mode
2 High QOS mode.
Default mode uses on-off keying signaling and BCH(63,51) code.
Non coherent receiver which is based on either energy detection(ED) or
autocorrelation.
Combination based single-stage and two-stage decode and forward relaying is
being considered.
Relay node is placed at a distance that measures exactly half of the total
distance between the source and destination nodes.
Half duplex communication.
Rayleigh distribution is used to model multipath fading.
4 May 2018 17 / 61

19. work done
The SNR at the energy detection receiver can be written as [12],
SNRDV =
2
Eb
No
4 + Np2TW
No
Eb
(2)
where;
Eb → integrated energy per bit.
N0 → noise power level
W → bandwidth of the signal.
Np →number of pulses per burst.
T → integration interval per pulse.
7
A. Rabbachin “Low complexity uwb receivers with ranging capabilities ”, Acta Universitatis Ouluensis, Series
C, Technica, vol. 298, 2008.
4 May 2018 18 / 61

20. work done
Since error correction capability of each of the NCW code word equals t, the
code word error probability can be calculated as [1]
pcw =
n
j=t+1
n
j
[pbu]j
[1 − pbu]n−j
(3)
where Pbu is the uncoded probability of error, and is given by;
pbu = Q( SNRr
DV ) (4)
Therefore, the bit error probability can be approximated as,
Pb =
1
n
pcw =
1
n
n
j=t+1
n
j
[pbu]j
[1 − pbu]n−j
(5)
Therefore, for the PSDU of total length l, the packet error probability can be
given by,
pe = 1 − (1 − pb)l
(6)
The probability of successful reception of PSDU is thus given by,
ps = 1 − pe (7)
4 May 2018 19 / 61

21. Packet success probability
1-relay cooperative scheme
assume pesd, pesr, perd represents the error probabilities of packet reception for
the s - d, s - r and r - d links respectively.
packet error happen either when both s - d and s - r links fail, or when s - d and
r - d links fail, at the same time s - r link is error free.
Hence, the packet error probability for 1-relay cooperative scenario can be
calculated as
pe1
cc = pesdpesr + pesd(1 − pesr)perd (8)
Accordingly, the success probability for the 1-relay cooperative scheme is
calculated as
ps1
cc = 1 − pe1
cc (9)
4 May 2018 20 / 61

22. Packet success probability
2-hop communication scheme
packet error occurs either when s-r links fail, or when r-d links fail, while s-r link
is error free.
Hence, the packet error probability for 2-hop scenario can be calculated as
pe2−hop = pesr + (1 − pesr)perd (10)
Accordingly, the success probability for the 2-hop scheme is calculated as
ps2−hop = 1 − pe2−hop (11)
4 May 2018 21 / 61

23. Packet success probability
2-relay cooperative scheme
packet error rates of source-to-relay r1 (s - r1), source - to - relay r2 (s - r2),
relay r1 - to -destination (r1 - d ) and relay r2-to-destination (r2 - d) links are
represented by pesr1, pesr2, per1d and per2d respectively.
If any of the following situations occur, the two-stage relaying fails:
The three links are fails, ie; s - d, s - r1 and s - r2 fail.
The direct communication and the first - stage relaying (through r1) results in a
failure, however, relay r2 cannot decode and forward the data packet because of
the failure of s - r2 link.
The direct communication and the first- stage relaying (through r1) fails and relay
r2 successfully decodes and forward the data packet, however but r2-d link fails.
The s - d and s - r1 links fail but if s - r2 link is error free , r2 decodes and
forwards but results in failure as a result of channel error in r2 - d link.
4 May 2018 22 / 61

24. Packet success probability
Therefore, packet error rate for two - stage relaying can be written as,
pe2
cc = pesdpesr1pesr2 + pesd(1 − pesr1)per1dpesr2+
pesd(1 − pesr1)per1d(1 − pesr2)per2d + pesdpesr1(1 − pesr2)per2d
(12)
Therefore probability of success for the two - stage relaying scheme can be
written as,
ps2
cc = 1 − pe2
cc (13)
4 May 2018 23 / 61

25. Energy Consumption Analysis
Energy Consumption Analysis
Cr−dl,Ct−dl Cr−ul,Ct−ul, are the energy consumption costs for reception and
transmission on the downlink and uplink scenarios respectievely.
Let Etx−ack / Erx−ack denote the enrgy required for transmission/reception of
acknowledgment packets.
Let Eenc / Edec be the energy required for data encoding/decoding.
Let Np represent the number of pulses per symbol.
Etx−p and Erx−p denote the total energy spent on transmission of a pulse and
that consumed by electronic circuits on reception of a pulse, respectively.
R is the coding date of data payload.
β is a modulation dependant parameter and is taken as 0.5 for on-off signaling.
4 May 2018 24 / 61

26. Energy Consumption Analysis
Direct Communication
Let Etx−d represent the energy required for transmitting a packet of l encoded
bits. Then
Etx−d =
βNpEtx−pCt−ul
R
l + Ct−ulEenc (14)
The Eenc is the encoding energy for BCH code rate, it could be calculated as,
Eenc = (2nt + 2t2
)(Eadd + Emul) (15)
where n ,t , Eadd ,Emul are the codeword length , error correcting capability,
addition energy consuption and multiplication energy consumption respectively.
4 May 2018 25 / 61

27. Energy Consumption Analysis
Similarly, the energy consumed by receiving node to receive the data packet can
be written as
Erx−d =
NpErx−pCr−ul
R
l + Cr−ulEdec (16)
The decoding energy(Edec) for BCH code rate can be calculated as,
Edec = (4nt + 10t2
)Emul + (4nt + 6t2
)Eadd + 3tEinv (17)
where Einv is the energy consumed for inversion operation.
4 May 2018 26 / 61

28. Energy Consumption Analysis
Similarly the energy utilization related with transmission or reception of
acknowledgment packets of size lack bits is written as,
Etx−ack =
βNpEtx−pCt−dl
R
lack (18)
Erx−ack =
NpErx−pCr−dl
R
lack (19)
Let the total energy expenditure required for data encoding and decoding and
for transmission and reception of the acknowledgment packets be denoted by Eo
which is expressed as follows :
E0 = Etx−ack + Erx−ack + Ct−ulEenc + Cr−ulEdec (20)
4 May 2018 27 / 61

29. Energy Consumption Analysis
Therefore the total energy spend for transfering a data packet of size l bits for
the direct communication (1-hop) can be expressed as,
E1−hop
total =
βNpEtx−pCt−ul
R
l +
NpErx−pCr−ul
R
l + Eo = x(Npl/R) + Eo (21)
where
x = βEtx−pCt−ul + Erx−pCr−ul (22)
Energy efficiency is formalized as the fraction of favorable energy for successful
communication of a packet of Lfb bits to the total consumed energy,it can be
computed as,
ηDC =
x(NpLfb/R)
x(Npl/R) + Eo
ps (23)
where Ps is the packet success rate.
4 May 2018 28 / 61

30. Energy Consumption Analysis
1-Relay cooperative Communication
To compute the average total energy consumption per bit of cooperative
communication (ECo
total) we consider three events :
The first event taken into account is the successful transmission of source to
destination link(s-d) in the 1st time slot which consumes energy E1with
probability (1 − pesd) .E1 can be written as,
E1 = Etx−d + 2Erx−d (24)
The second event considered is the transmission failure of source to destination
link(s-d) and source to relay link(s-r) in the 1st time slot together,which spend an
energy E2 with probability pesdpesr .E2 can be expressed as,
E2 = Etx−d + 2Erx−d (25)
The third event considered is the transmission failure of source to destination link,
and the successful transmission of source to relay link in the 1st time slot in the
meantime which expends energy E3 with probability pesd(1 − pesr). E3can be
expressed as,
E3 = 2Etx−d + 3Erx−d (26)
4 May 2018 29 / 61

31. Energy Consumption Analysis
Therefore, total energy expenditure of cooperative communication in average
can be expressed as,
E1−cc
total = E1(1 − pesd)+E2pesdpesr
+E3pesd(1 − pesr) (27)
The total energy spend for the transmission of acknowledgment packets in
cooperative communication (Ecc,ack) can be written as,
E1
cc,ack = (Etx−ack + 2Erx−ack)[1 + pesd(1 − pesr)] (28)
Here E1
cc,ack is total energy expenditure related with transmission of either ack
or nack by the destination in first and second phase.Transmission of ack/nack in
the second phase happens with probability pesd(1 − pesr).
Therefore energy efficiency for single -stage cooperative scheme can be written
as,
η1
cc =
x(NpLfb/R)
Eco
total + Ecc,ack
p1
s,cc (29)
4 May 2018 30 / 61

32. Energy Consumption Analysis
2-Hop Communication
In order to calculate the total energy consumption involved in successful
transmission of a packet, we consider two events :
Failure of transmission from source to relay nodes in the 1st time slot → which
consumes energy E1 with probability (1 − pesr).
Event 2 is the transmission failure of source to relay link in the 1st time slot which
utilize an energy E2 with probability pesr. E1 and E2can be written as,
E1 = 2E2 = 2{Etx−d + Erx−d} (30)
Total energy consumption of 2 - hop communication in average is expressed as,
E
2−hop
total
= E1(1 − pesr) + E2pesr (31)
4 May 2018 31 / 61

33. Energy Consumption Analysis
The total energy spend for transmission of acknowledgment packets in 2-hop
communication (E2−hop,ack), can be written as,
E2−hop,ack = (Etx−ack + Erx−ack)[1 − pesr] (32)
Therefore energy efficiency of 2-hop communication can be written as,
η2−hop =
x(NpLfb/R)ps2−hop
E2−hop
total + E2−hop,ack
(33)
4 May 2018 32 / 61

34. Energy Consumption Analysis
2-Relay cooperative Communication
To compute the average total energy consumption per bit of cooperative
communication , we consider the following events :
Direct communication is sucessful,with probability (1 − pesr), total energy
consumed in this case is (Etx−d + 3Erx−d)
The s - d link fails, whereas s-r1 link is error free, and the relay r1 decode and
forward the packet with probability pesd(1 − pesr1), causing an energy
expenditure in total as (2Etx−d + 4Erx−d)
Both s - d and s - r1 links fail, whereas s-r2 link is error free. Total probability
corresponds to these events is pesdpesr1(1 − pesr2) and the energy expense is same
as in the earlier case (case ii).
4 May 2018 33 / 61

35. Energy Consumption Analysis
The s - d link fails, whereas s-r1 link is error free, and relay r1 forward the packet
after decoding , but r1 - d link and s - r2 is in error. Total probability corresponds
to these events is, pesd(1 − pesr1)per1dpesr2 and the energy expense is same as in
the earlier case .
The s - d link fails, whereas s - r1 link is error free but r1 - d link is in error
.Though , the s - r2 link is error free,and the relay r2 forward the packet after
decoding. The probability of this event is pesd(1 − pesr1)per1d(1 − pesr2) and the
energy consumed in this case is (3Etx−d + 5Erx−d)
The s-d link, s-r1 link and s-r2 link are in fail with probability pesdpesr1pesr2 and
the energy consumed in this case is (Etx−d + 3Erx−d)
4 May 2018 34 / 61

36. Energy Consumption Analysis
Therefore the energy consumption in total for the data packet transmission can be
calculated as,
E2−cc
total
= (Etx−d + 3Erx−d)(1 − pesd)
+ (2Etx−d + 4Erx−d)pesd(1 − pesr1)
+ (2Etx−d + 4Erx−d)pesdpesr1(1 − pesr2)
+ (2Etx−d + 4Erx−d)Pesd(1 − pesr1)per1dpesr2
+ (3Etx−d + 5Erx−d)pesd(1 − pesr1)Per1d(1 − pesr2)
+ (Etx−d + 3Erx−d)pesdpesr1pesr2
(34)
Likewise, the energy consumption in total for transmission of an ack/nack packet
can be calculated as,
E2
cc,ack = (Etx−ack + 3Erx−ack) + (Etx−ack + 3Erx−ack)pesd(1 − pesr1)
+ (Etx−ack + 2Erx−ack)pesd(1 − pesr1)per1d(1 − pesr2)
+ (Etx−ack + 2Erx−ack)pesdpesr1(1 − pesr2)
(35)
4 May 2018 35 / 61

37. Energy Consumption Analysis
Therefore, energy efficiency of two-stage cooperative communication can be
calculated as :
η2
cc =
x(NpLfb/R)
E2−cc
total
+ E2
cc,ack
p2
s,cc (36)
4 May 2018 36 / 61

38. Optimal packet size
OPTIMAL PACKET SIZE
An optical packet size is charecterized as the packet which has a payload size
that maximizes energy efficiency
It can be derived by taking dη
dLfb
= 0 where η denotes the energy efficiency of
direct, 2-hop and 1-stage/2-stage cooperative communication scenarios.
In the case of direct communication, the optimal packet size can be derived as ,
LOpt
1−hop = −
v
2
+
1
2
v2 −
4v
ln(1 − pe)
(37)
where v = EoR
xwNp
,Here w=1+ r
k
, where r = n
k
is code rate.
4 May 2018 37 / 61

39. Optimal packet size
Table 1: 3: UWB System Related Parameters [1]
W 499.2MHz
Np 32
T 2ns
Etx−ul 0.9
Erx−dl 0.9
Erx−ul 0.1
Etx−dl 0.1
Eenc 4pJ
Edec 2nJ
Etx−p 20pJ
Erx−p 2.5nJ
R 487Mbps
Nack 144
N0(dBm) -100
4 May 2018 38 / 61

40. Simulation results
SIMULATION RESULTS
OOK modulation with 2-ary waveform coding is applied to the required number
of bits which are BCH encoded according to the IEEE 802.15.6 standard
specification
distance dependent path loss, lognormal shadowing and additive white gaussian
noise are then introduced into the simulations
The receiver employs decoding and demodulation followed by energy based
detection
4 May 2018 39 / 61

41. Simulation results
10 15 20 25 30 35 40 45 50
S-D Hop distance in cm
10-8
10-6
10-4
10-2
100
Packeterrorrate
direct analysis
direct simulation
1-rel cop analysis
1-rel cop simulation
2-rel cop analysis
2-rel cop simulation
2-hop analysis
2-hop simulation
Figure 1: Packet error rate v/s source to destination hop distance for on-body NLOS channel
(packet size 500 bits).
4 May 2018 40 / 61

42. Simulation results
10 15 20 25 30 35 40 45 50
S-D Hop distance in cm
10-9
10-8
10-7
10-6
10-5
10-4
10-3
10-2
10-1
100Packeterrorrate
direct analysis
direct simulation
2-hop analysis
2-hop simulation
2-rel cop analysis
2-rel cop simulation
1-rel cop analysis
1-rel cop simulation
Figure 2: Packet error rate v/s source to destination hop distance for in-body channel
(packet size 500 bits).
4 May 2018 41 / 61

43. Simulation results
50 100 150 200 250 300
S-D hop distance in cm
10-9
10-8
10-7
10-6
10-5
10-4
10-3
10-2
10-1
100
Packeterrorrate
direct analysis
direct simulation
2-hop analysis
2-hop simulation
2-rel cop analysis
2-rel cop simulation
1-rel cop analysis
1-rel cop simulation
Figure 3: Packet error rate v/s source to destination hop distance for on-body LOS channel
(packet size 500 bits).
4 May 2018 42 / 61

44. Simulation results
-40 -35 -30 -25 -20 -15 -10 -5
transmit power(dBm)
0.4
0.5
0.6
0.7
0.8
0.9
1
energyefficiency
direct
cooperative
Figure 4: Energy efficiency v/s transmit power for on-body NLOS communication. at a s-d
hop distance of 7cm (packet size 500 bits).
4 May 2018 43 / 61

45. Simulation results
-40 -35 -30 -25 -20 -15 -10 -5
transmit power(dBm)
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
energyefficiency
direct
cooperative
Figure 5: Energy efficiency v/s transmit power for on-body NLOS communication. at a s-d
hop distance of 17cm (packet size 500 bits).
4 May 2018 44 / 61

46. Simulation results
-40 -35 -30 -25 -20 -15 -10 -5
transmit power(dBm)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
energyefficiency
direct
cooperative
Figure 6: Energy efficiency v/s transmit power for on-body NLOS communication. at a s-d
hop distance of 47cm (packet size 500 bits).
4 May 2018 45 / 61

47. Simulation results
-40 -35 -30 -25 -20 -15 -10 -5
transmit power(dBm)
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
energyefficiency
direct
cooperative
Figure 7: Energy efficiency v/s transmit power for on-body NLOS communication. at a s-d
hop distance of 67cm (packet size 500 bits).
4 May 2018 46 / 61

48. Simulation results
-40 -35 -30 -25 -20 -15 -10 -5
transmit power(dBm)
0
0.05
0.1
0.15
0.2
0.25
0.3
energyefficiency
direct
cooperative
Figure 8: Energy efficiency v/s transmit power for on-body NLOS communication. at a s-d
hop distance of 117cm (packet size 500 bits).
4 May 2018 47 / 61

49. Simulation results
0 500 1000 1500
packet size ( in bits)
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
energyefficiency
direct (d=13 cm)
1-rel (d=13 cm)
2-rel (d=13 cm)
2-hop (d=13 cm)
direct(d=25 cm)
1-rel (d=25 cm)
2-rel (d=25 cm)
2-hop (d=25 cm)
Figure 9: Energy efficiency v/s packet size for in-body channel at s-d hop length of 27cm.
4 May 2018 48 / 61

50. Simulation results
0 500 1000 1500
packet size (in bits)
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
energyefficiency
drect (d=17cm)
1-rel (d=17 cm)
2-rel (d=17 cm)
2-hop(d=17 cm)
direct(d=37 cm)
1-rel(d=37 cm)
2-rel(d=37 cm)
2-hop(d=37 cm)
Figure 10: Energy efficiency v/s packet size for On-body NLOS channel at s-d hop length of
20cm
4 May 2018 49 / 61

51. Simulation results
0 500 1000 1500
packet size(in bits)
0
0.1
0.2
0.3
0.4
0.5
0.6
energyefficiency
drect (d=117 cm)
1-rel (d=117cm)
2-rel (d=117 cm)
2-hop (d=117 cm)
direct (d=250 cm)
1-rel (d=255 cm)
2-rel (d=255 cm)
2-hop (d=255 cm)
Figure 11: Energy efficiency v/s packet size for on-body NLOS channel at s-d hop length of
42cm.
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52. Simulation results
0 10 20 30 40 50 60
S-D hop distance ( in cm)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
energyefficiency
direct
1-rel cop
2-rel cop
2-hop
Figure 12: Energy efficiency v/s source to destination hop distance for in-body channel
(packet size 350 bits).
4 May 2018 51 / 61

53. Simulation results
0 10 20 30 40 50 60
S-D hop distance ( in cm)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
energyefficiency
drect
1-rel cop
2-rel cop
2-hop
Figure 13: Energy efficiency v/s source to destination hop distance for on-body NLOS
channel (packet size 350 bits).
4 May 2018 52 / 61

54. Simulation results
0 100 200 300 400 500 600
S-D hop distance (in cm)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
energyefficiency
direct
1-rel cop
2-rel cop
2-hop
Figure 14: Energy efficiency v/s source to destination hop distance for on-body LOS channel
(packet size 350 bits).
4 May 2018 53 / 61

55. Simulation results
Table 2: Threshold value of source to destination hop length for packet size=350 bits
.
WBAN Scenarios Threshold distance(in cm)
in-body 14
on-body (NLOS) 19
on-body (LOS) 130
Table 3: Comparison of maximum achievable hop distance (cm) providing energy
efficient communication for different communication scenarios
WBAN Scenarios in-body on-body (NLOS) on-body (LOS)
Direct 18 28 220
1-relay Cooperative 37 52 440
2-relay Cooperative 37 52 440
2-hop 42 60 600
4 May 2018 54 / 61

56. Simulation results
Table 4: Comparison of optimal packet size (bits)
WBAN Scenarios in-body on-body (NLOS) on-body (LOS)
Direct 300 300 300
1-relay Cooperative 600 650 500
2-relay Cooperative 700 800 680
2-hop 550 650 600
4 May 2018 55 / 61

57. Conclusion
Conclusion
Energy efficiency in the default mode of IR-UWB PHY in the IEEE 802.15.6 for
an AWGN channel with path loss model for direct,2-hop and cooperative
communication(single-relay and two-relay) scenarios has been analyzed .
Energy efficiency of different communication scenarios (on body- LOS and
NLOS ,in body) have been evaluated by including the impact of packet error
rate into the analysis.
Compared to direct transmission cooperative communication offers higher packet
success rates and also better efficiency values when the source-destination hop
length exceeds a certain threshold.
The optimal packet size for energy efficient cooperative communication has been
observed to be larger than that of direct communication.
4 May 2018 56 / 61

58. Conclusion
Under shadowing effects, adoption of cooperative communication techniques will
improve the energy efficiency, support larger packet size and will increase the
hop length.
Energy efficiency of 2-hop communication in multipath fading is also
investigated.
2-hop communication provides the maximum energy efficiency and the highest
optimal payload size when channel is poor.
In in-body channel, 2-hop or cooperative communications are very necessary
when 1-hop communication is not feasible.
Two-relay technique in co-operative scheme does not increase energy efficiency
comapred to one-relay case.
It is observed that PER is lower when two relays are made use for cooperation
compared with single- relay case.
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59. References
References
[1] IEEE standard for local and metropolitan area networks - Part 15.6. Wireless Body Area Networks, 29
February 2012.
[2] Ian Oppermann, Matti Hamalainen and Jari Iinatti. UWB Theory and Applications. University of
Oula:Finland.
[3] A. K. Sadek, W. Yu, and K. J. Liu, “On the energy efficiency of cooperative communications in wireless
sensor networks ”, in ACM Trans. on Sensor Networks (TOSN) , vol. 6 no. 1, pp. 5.1-5.21, Dec 2009.
[4] K. Deepak and A. Babu, “Improving energy efficiency of incremental relay based cooperative
communications in wireless body area networks ”, in International Journal of Communication Systems, 2013.
[5] M. C. Domingo, “Packet Size Optimization for Improving the Energy Efficiency in Body Sensor
Networks” , in ETRI Journal, vol. 33, no. 3, pp. 299-309, Jun 2011.
[6] Mohammad Sadegh Mohammadi, Qi Zhang, Eryk Dutkiewicz, and Xiaojing Huang ,“Optimal Frame
Length to Maximize Energy Efficiency in ieee 802.15.6 IR- UWB Body Area Networks” in IEEE Wireless
Communications Letters, vol. 3, no. 4, pp. 397-400, 2014.
4 May 2018 58 / 61

60. References
[7] Nattakorn Promwongsa,TeerapatSanguankotchakorn,“Packet Size Optimization for Energy-Efficient
2-hop in Multipath Fading for WBAN”, in The 22nd Asia-Pacific Conference on Communications.,
Yogyakarta,Indonesia,pp.445-450, August 2016.
[8] D. Jie, E. Dutkiewicz, X. Huang and G. Fang., “Energy-efficient cooperative relay selection for UWB
based body area networks ”, in IEEE International Conference in Ultra-Wideband(ICUWB), 2013, pp.97-102.
[9] Kemal Davaslioglu, Yang Liu, and Richard D. Gitlin,“CLOEE - Cross-Layer Optimization for Energy
Efficiency of IEEE 802.15.6 IR-UWB WBANs” , in IEEE GLOBECOM ., December 2016 Washington DC.
[10] A. Khaleghi, R. Ch´avez-Santiago, and I. Balasingham,“Ultra-wideband statistical propagation
channel model for implant sensors in the human chest”, in IET microwaves, antennas and propagation , vol.
5, no. 15, pp. 1805–1812, 2011.
[11]G. Dolmans and A. Fort, “Channel models WBAN”, Holst centre /IMECNL,IEEE
802.15-08-0418-01-0006, July 2008.
4 May 2018 59 / 61

61. References
[12] A. Rabbachin, “Low complexity uwb receivers with ranging capabilities”, in Acta Universitatis
Ouluensis, Series C, Technica, vol. 298, 2008.
[13] J. G. Proakis, Digital Communications. Wiley Online Library, 2001.
[14] Fort A, Ryckaert J, Desset C, De Doncker P, Wambacq P, Van Biesen L,“Ultra-wideband channel
model for communication around the human body”,in IEEE Journal on Selected Areas in Communications
2006; 24:927–933.
[15] Princy Maria Paul, A. V. Babu,“Frame Length Optimization in IEEE 802.15.6 UWB Cooperative
Body Area Networks”, in IEEE Recent Advances in Intelligent Computational Systems (RAICS),
Trivandrum,pp.99-104 December 2015.
[16] R. Yu, Y. Zhang, and R. Gao, “Mobile device aided cooperative transmission for body area networks”,
in Proc. of ACM International Conference on Body Area Networks, pp 65-70, Corfu, Greece, Sep 2010.
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