Combination of wisemac and proposed transceiver method for WBAN

In this paper, we proposed two-way communications in which after receiving a data, the sensor immediately reply a data instead of ACK to the hub or the hub immediately transfer the received data forward the control node. It is called to be transceiver unification.

Nghiên cứu khoa học công nghệ COMBINATION OF WISEMAC AND PROPOSED TRANSCEIVER METHOD FOR WBAN Vu Van Son* Abstract: Recently, since demands of wireless body area networks (WBAN) increase, a standard of WBAN called IEEE 802.15.6 was established in Feb., 2012 Bi-directional communications are possible in IEEE 802.15.6; however, uplinks and downlinks are independent meaning data are independently transmitted on downlinks and uplinks Therefore, delays, power consumptions are increased In this paper, we proposed two-way communications in which after receiving a data, the sensor immediately reply a data instead of ACK to the hub or the hub immediately transfer the received data forward the control node It is called to be transceiver unification The proposed algorithm improves performances of WBAN because of reduction the delay of data, omitting ACK, decreasing the waiting time of the hub or the control node Since WiseMAC can decrease power consumptions while decreasing the delay, the WiseMAC is taken into consideration The performance of WBAN based on combination of WiseMAC and transceiver unification is analyzed and the proposed algorithm shows that the power consumption is more efficient than that of conventional algorithm while maintaining the same delay Keywords: IEEE 802.15.6, WiseMAC, WBAN, Control communication, Power consumption INTRODUCTION Recently, small wireless devices used in/on/ around human body area are developed rapidly by a miniaturization technology These devices are expected to be used in the medical field Furthermore, these devices are expected to suppose elder man and a lifestyle-related disease patient So since demands of wireless body area networks (WBAN) increases from such a scene IEEE 802.15.6 was established in Feb., 2012 [1] The bi-directional communication is possible in IEEE 802.15.6，both devices can get each other's various information In addition, Ultra Wide Bands (UWB) is adopted in the standard due to its low interference and low effect to body [2,3] Since there is the interference between several sensors, the communication between hubs is requested to avoid the interference There are several researches about medium access controls (MAC), these researches focused on the carrier sense multiple access with collision avoidance (CSMA/CA) in cases the system model is non-saturation [4], saturation [5] or time-saturation [6] In order to improve the performance of system, the cluster-base WBAN [7] and the multiple-hop WBAN [8] were proposed and analyzed based on CSMA/CA However, the MAC and access schemes which are defined in the standard can’t solve the problems of WBAN plentifully A efficient control scheme for WBAN should be proposed In this paper, uplinks and downlinks are taken into account Data are independently transmitted on downlink (from the hub to a node) and uplink (from a node to the hub) because a communication slot of downlink and uplink is assigned separately when a node and/or the hub have the data to send Thus, efficiencies of two-way communications are low, and the delay is large when the data is transmitted between sensors and the hub Consequently, in order to improve the performance of this system, we proposed an algorithm that the sensor immediately replies a data instead of ACK after receiving a data request from the hub Moreover, the hub immediately transfers the received data from a sensor to the control node and a WiseMAC [3] is adopted Tạp chí Nghiên cứu KH&CN quân sự, Số 50, 08 - 2017 119 Kỹ thuật điều khiển & Điện tử The rest of paper is as follows The system model and the WiseMAC are described in Sections and 3, respectively The numerical simulation result is represented in Section Finally, Section concludes the paper SYSTEM MODEL Figure The communication model of proposed algorithm A system that described in Fig is taken into consideration It consists of several sensor nodes, one control node and a hub which transfers the data between sensor nodes and the control node The system also has one or more other nodes that communicate with the hub in two-way communication Figure Transmission and reception unification method by the transmission demand It is considered that there are two scenarios of communications between sensors and the control node One is sensors transmit their data in every constant interval Moreover, sensors only transmit their data after receiving the data request from the hub Comparing to the former one, the later one has low power consumption, low delay and it requests low throughput The process of communications between the control node and sensors are shown in Fig and explained as follows 1) The control node transmits communication demand data to the hub 2) The hub transfers the communication demand data to sensors 3) The sensor that received the communication demand data immediately transmits its data to the hub 4) The hub immediately transfers the received data to the control node and the control node replies a L-ACK to the hub and the sensor However, there are the problems that a huge gap of the time produces because the wake up timing of the hub and sensors isn’t synchronized Therefore, the WiseMAC is used to 120 Vu Van Son, “Combination of WiseMAC and proposed transceiver method for WBAN.” Nghiên cứu khoa học công nghệ communicate between the hub and sensors The next section shows the proposed of the transmission and reception based on WiseMAC WISEMAC FOR TWO-WAY COMMUNICATIONS In order to improve the power consumption and solves the problem of synchronization, a MAC scheme that is called WiseMAC is adopted [3] Because of unnecessary of synchronization between communicated nodes and the short preamble of required transmission, the WiseMAC can enhance the performance of WBANs Fig shows the algorithm of WiseMAC protocol for transmission and reception as a time chart of concrete communication In the conventional WiseMAC, the sensor repeats sleeping and listening states every constant interval In the sleeping state, sensors can’t communicate, however the power consumption is considerably low In contrast, in the listening state, sensors can receive data, however it consumes the higher power than the sleeping state In addition, a length of preamble equals to (4θL, Tw), here θ expresses a frequency deviation of the wakeup time, L denotes transmission time for data intervals, Tw represents the time duration between wakeups Figure The WiseMAC for transmission and reception unification However, in WiseMAC for transmission and reception unification, if the hub has the data for the sensor, the hub transmits the data to the sensor after the transmission of preamble without delay In addition, the sensor transmits sensing data instead of ACK, and the hub doesn’t send an ACK to the sensor after receiving a data from the sensor It is possible to perform this protocol because the sensor doesn’t transmit a data unless the hub gives demands In this moment, the sensor doesn’t know whether the data is correctly transmitted to the hub or not However, after receiving the data from the sensor, the hub transfers it to the control node, and the control node replies the L-ACK to the hub and the sensor The sensor turns to sleeping state if it receives the ACK and retransmits the data if it receives the NACK SIMULATION RESULT 4.1 System parameter The simulation was operated according to system parameter summarized in Table In addition, it was examined under the low-traffic condition; the packet generation time of every sensor is about 100 second This is because much medical equipment doesn’t request frequent communication, except in case of emergency Moreover, this simulation Tạp chí Nghiên cứu KH&CN quân sự, Số 50, 08 - 2017 121 Kỹ thuật điều khiển & Điện tử considers that there is not influence of packet loss caused by a noise and the timeout The simulation model is shown in Fig Table Simulation parameters The simulation model is explained as follows The sensor turns alternatively to sleeping and listening states in the asynchronous operation The control node transmits communication demand data to the hub and the hub request sensors transmit their data Figure Simulation model After receiving the data, the hub transfers the sensing data to the control node Finally, the control node replies the ACK to the hub and sensors The communication between the hub and sensors follows the WiseMAC that is explained above A cycle is defined as from the control node sends the communication demand data until it replies the ACK to the hub and sensors The simulation result is the average result of all cycles The number of cycle is denoted by the transmission number of times The performance of proposed protocol is compared to the conventional protocol based on power consumption and the delay Furthermore, the Polling protocol showing in Fig for comparison with the proposed protocol This method is handled like a method used in MAP section of IEEE802.15.6 Sensors transmit their data to the hub in every constant interval regardless communication demand data of the control node and the hub 122 Vu Van Son, “Combination of WiseMAC and proposed transceiver method for WBAN.” Nghiên cứu khoa học công nghệ Figure Polling protocol The simulation result, such as power consumption and delay, is shown in the following section 4.2 Effect of the power consumption We show the graph of the result of the power consumption for both the proposed and the Polling protocols in Fig Compare to the Polling protocol, the power consumption of proposed protocol is lower, especially when the wakeup period is small It is explained as that the listening state time of proposed protocol is shorter than that of Polling protocol Furthermore, when the wakeup period increases, the power consumption of two protocol will be decreased However, the power consumption of Polling protocol decreases more rapidly than that of proposed protocol and the power consumption of both protocols becomes equally when the wakeup period is greatly high Figure The power consumption of sensors Tạp chí Nghiên cứu KH&CN quân sự, Số 50, 08 - 2017 123 Kỹ thuật điều khiển & Điện tử In addition, the maximum and the minimum of the power consumption is considered As shown in Fig 6, the shorter the wake up priod is ,the higher power consumption of sensors is The reason is considered as that although sensors don’t have to transmit their data, the number and the time duration of listening states increase, and the sleep state period is decreased Thus, the power consumption achieves the maximum when sensors always be in the listening state and transmit/receive the data The maximal power consumption is the sum of power consumption of listening state and the power consumption to transmit/ receive the data, it is about 1.8 mW On the contrary, the longer the wake up priod is, the lower power consumption of sensing node is Moreover, the power consumption achieves the minimum when sensors are in only the sleep state and the power consumption to transmit is smallest (preamble is shortest), it is about 432μW 4.3 Effect of the delay time Figure Delay time by the wake-up period of the sensing node We show the delay time of both proposed and the Polling protocols in Fig This delay time shows the processing time required for the transmission of corresponding data after occurring of a transmission request meaning the time for a cycle As shown in Fig 7, it is considered that the longer the wake up priod is ,the longer the delay time is Moreover, the ideal minimum delay time becomes 16ms, whereas the maximum does not exist In addtion, there are small differences in delay time between proposed protocol and the Polling protocol When a wake up period is short, delay time of the Polling protocol slightly becomes smaller than the proposed protocol, however, it can be said that the delay time of both protocols are the same 4.4 Delay time based power consumption Finally, we show the graph of the result of the delay time based power consumption of both protocols in Fig From Fig 8, it is recognized that the power consumption of the proposed protocol is better than that of Polling protocol when delay time is small However, when delay time is high, the proposed and Polling have the same power consumption 124 Vu Van Son, “Combination of WiseMAC and proposed transceiver method for WBAN.” Nghiên cứu khoa học công nghệ Figure Power consumption by delay time As explanation above, it can be said that the proposed protocol overcomes the Polling protocol based on the power consumption CONCLUSION This paper has proposed a protocol based on WiseMAC for the transmission and reception unification The power consumption and the delay time were analyzed under low traffic conditions it is showed that the proposed protocol is more efficient and the power consumption could be improved without increasing delay time However, there are many points that we must considerer, such as communication distances, interferences of other BAN and so on Additionally, in order to adopt this proposed protocol in ad hoc networks where there are many BANs, the interference between hubs should be considered Furthermore, the security of medical data is an important problem because incorrect medical data affects the human body We leave them to the future work REFERENCES [1] IEEE 802.15 WPAN Task Group Available online: http://www.ieee802.org/15/pub/TG6.html [2] Guan-Tsang Chen, Shan-Hsiang Shen, and W T Chen, “2L-MAC: A MAC Protocol with Two-Layer Interference Mitigation in Wireless Body Area Networks for Medical Applications,” IEEE ICC, Sydney, Australia, (2014) [3] A El Hoiydi, J.D.Decotignie “WiseMAC: An Ultra-Low Power MAC Protocol for the Downlink of Infrastructure Wireless Sensor Networks,” Rue Jaquet Droz 1, Neuchatel, Switzerland, (2007) [4] S Rashwand and J Misic,“Performance evaluation of IEEE 802.15.6 under nonsaturation condition” Proc the IEEE Global Telecommun Conf (GLOBECOM 11), pp 1–6, (2011) 
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 [6] Pham Thanh Hiep, “Statistical method for performance analysis of WBAN in time- Tạp chí Nghiên cứu KH&CN quân sự, Số 50, 08 - 2017 125 Kỹ thuật điều khiển & Điện tử saturation,” EURASIP Journal on Wireless Communications and Networking,
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 [7] Pham Thanh Hiep “Spatial reuse superframe for high throughput cluster-based WBAN with CSMA/CA,” Ad-Hoc and Sensor Wireless Networks, Vol 31, No 1–4, pp.69–87, (2014) [8] Pham Thanh Hiep, Nguyen Huy Hoang, and Ryuji Kohno, “Performance Analysis of Multiple-Hop Wireless Body Area Network,” Journal of communication and networks, Vol 17, No 4, pp 419–427, (2015) TÓM TẮT KẾT HỢP WISEMAC VỚI PHƯƠNG PHÁP TRUYỀN NHẬN DỮ LIỆU ĐƯỢC ĐỀ XUẤT CHO MẠNG WBAN Nhằm đáp ứng yêu cầu ngày cao mạng vô tuyến quanh thể, chuẩn IEEE 802.15.6 đời vào tháng năm 2012 Trong chuẩn IEEE 802.15.6, thông tin hai chiều thiết lập, nhiên đường lên đường xuống xử lý độc lập nhau, thời gian trễ, lượng tiêu hao tăng cao Trong báo này, tác giả đề xuất phương pháp truyền nhận liệu sử dụng cho thông tin hai chiều Trong đó, sau nhận tín hiệu u cầu từ nút phân phối, cảm biến gửi liệu thay cho ACK, nút phân phối chuyển tiếp liệu cho nút điều khiển sau nhận liệu từ cảm biến Phương thức truyền nhận liệu làm tăng chất lượng hệ thống giảm thời gian trễ liệu, loại bỏ tập tin ACK, giảm thời gian chờ tập tin nút phân phối Phương pháp đề xuất kết hợp với WiseMAC để nâng cao chất lượng hệ thống Bài báo thực phân tích, so sánh phương pháp đề xuất với phương thức TDMA Kết cho thấy lượng tiêu thụ phương thức đề xuất thấp so với lượng tiêu thụ phương thức truyền thống giữ nguyên thời gian trễ Từ khoá: IEEE 802.15.6, WiseMAC, WBAN, Điều khiển truyền tin, Năng lượng tiêu thụ Received date, 07th August, 2017 Revised manuscript, 09th August, 2017 Published, 18th August, 2017 Author affiliations: Military Technical Academy * Corresponding author: sonthuy0912@gmail.com 126 Vu Van Son, “Combination of WiseMAC and proposed transceiver method for WBAN.” ... synchronized Therefore, the WiseMAC is used to 120 Vu Van Son, Combination of WiseMAC and proposed transceiver method for WBAN. ” Nghiên cứu khoa học công nghệ communicate between the hub and sensors... interval regardless communication demand data of the control node and the hub 122 Vu Van Son, Combination of WiseMAC and proposed transceiver method for WBAN. ” Nghiên cứu khoa học công nghệ... Son, Combination of WiseMAC and proposed transceiver method for WBAN. ” Nghiên cứu khoa học công nghệ Figure Power consumption by delay time As explanation above, it can be said that the proposed