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A statistical frame based TDMA protocol for human body communication.

Nie Z, Li Z, Huang R, Liu Y, Li J, Wang L - Biomed Eng Online (2015)

Bottom Line: A beacon frame with the contained synchronous and poll information is designed to reduce the possibility of collisions of request frames.Dynamic time slot allocation mechanism is presented to manage the burst traffic and reduce the active period in each beacon period.The theory analysis is proceed and the result is evaluated in the hardware platform.

View Article: PubMed Central - PubMed

Affiliation: Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518005, China. zd.nie@siat.ac.cn.

ABSTRACT

Background: Human body communication (HBC) using the human body as the transmission medium, which has been regarded as one of the most promising short-range communications in wireless body area networks (WBAN). Compared to the traditional wireless networks, two challenges are existed in HBC based WBAN. (1) Its sensor nodes should be energy saving since it is inconvenient to replace or recharge the battery on these sensor nodes; (2) the coordinator should be able to react dynamically and rapidly to the burst traffic triggered by sensing events. Those burst traffic conditions include vital physical signal (electrocardiogram, electroencephalogram etc.) monitoring, human motion detection (fall detection, activity monitoring, gesture recognition, motion sensing etc.) and so on. To cope with aforementioned challenges, a statistical frame based TDMA (S-TDMA) protocol with multi-constrained (energy, delay, transmission efficiency and emergency management) service is proposed in this paper.

Methods: The scenarios where burst traffic is often triggered rapidly with low power consumption and low delay is handled in our proposed S-TDMA. A beacon frame with the contained synchronous and poll information is designed to reduce the possibility of collisions of request frames. A statistical frame which broadcasts the unified scheduling information is adopted to avoid packet collisions, idle listening and overhearing. Dynamic time slot allocation mechanism is presented to manage the burst traffic and reduce the active period in each beacon period. An emergency mechanism is proposed for vital signals to be transmitted. The theory analysis is proceed and the result is evaluated in the hardware platform.

Results: To verify its feasibility, S-TDMA was fully implemented on our independently-developed HBC platform where four sensor nodes and a coordinator are fastened on a human body. Experiment results show that S-TDMA costs 89.397 mJ every 20 s when the payload size is 122 bytes, 9.51% lower than Lightweight MAC (LMAC); the average data latency of S-TDMA is 6.3 ms, 7.02% lower than Preamble-based TDMA (PB-TDMA); the transmission efficiency of S-TDMA is 93.67%, 4.83% higher than IEEE 802.15.6 carrier sense multiple access/collision avoidance (CSMA/CA) protocol.

Conclusions: With respect to the challenges of HBC based WBANs, a novel S-TDMA protocol was proposed in this paper. Compared to the traditional protocols, the results demonstrate that S-TDMA successfully meets the delay and transmission efficiency requirements of HBC while keeping a low energy consumption. We also believe that our S-TDMA protocol will promote development of HBC in wearable applications.

No MeSH data available.


Related in: MedlinePlus

Comparison of transmission efficiency among the four protocols with the payload size of data frame increased. This figure shows that by using request frame and statistical frame, S-TDMA can get higher transmission efficiency in comparison with the other protocols.
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Fig12: Comparison of transmission efficiency among the four protocols with the payload size of data frame increased. This figure shows that by using request frame and statistical frame, S-TDMA can get higher transmission efficiency in comparison with the other protocols.

Mentions: Sending, receiving, and listening for overhead can be a source of energy wastage [40]. To measure the influence of overhead of the superframe, we calculated the transmission efficiency of S-TDMA and that of the other three protocols. Transmission efficiency counts not only with the data bits but also with the overhead that makes use of the channel. Control packet overhead is a major source of energy that we consider here. Sending, receiving, and listening for control packets consume energy. Since, control packets do not directly convey useful application data; they also reduce the effective throughput. In this experiment, the transmission overhead consists of beacon frame, request frame, statistical frame, acknowledge frame and the bytes aside from the data packet in a data frame. The following assumptions are considered for calculation: (a) the channel is noise free; (b) there is no data loss during the transmission, namely: no retransmission is needed. We calculate the transmission efficiency of S-TDMA and the other three protocols according to the transmission efficiency analysis. The transmission efficiency of all the four protocols is illustrated in Figure 12. Though the utilization of request frame and statistical frame can inevitably lead to an increase in overhead, the transmission efficiency of S-TDMA is still higher than the other three protocols.Figure 12


A statistical frame based TDMA protocol for human body communication.

Nie Z, Li Z, Huang R, Liu Y, Li J, Wang L - Biomed Eng Online (2015)

Comparison of transmission efficiency among the four protocols with the payload size of data frame increased. This figure shows that by using request frame and statistical frame, S-TDMA can get higher transmission efficiency in comparison with the other protocols.
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4495947&req=5

Fig12: Comparison of transmission efficiency among the four protocols with the payload size of data frame increased. This figure shows that by using request frame and statistical frame, S-TDMA can get higher transmission efficiency in comparison with the other protocols.
Mentions: Sending, receiving, and listening for overhead can be a source of energy wastage [40]. To measure the influence of overhead of the superframe, we calculated the transmission efficiency of S-TDMA and that of the other three protocols. Transmission efficiency counts not only with the data bits but also with the overhead that makes use of the channel. Control packet overhead is a major source of energy that we consider here. Sending, receiving, and listening for control packets consume energy. Since, control packets do not directly convey useful application data; they also reduce the effective throughput. In this experiment, the transmission overhead consists of beacon frame, request frame, statistical frame, acknowledge frame and the bytes aside from the data packet in a data frame. The following assumptions are considered for calculation: (a) the channel is noise free; (b) there is no data loss during the transmission, namely: no retransmission is needed. We calculate the transmission efficiency of S-TDMA and the other three protocols according to the transmission efficiency analysis. The transmission efficiency of all the four protocols is illustrated in Figure 12. Though the utilization of request frame and statistical frame can inevitably lead to an increase in overhead, the transmission efficiency of S-TDMA is still higher than the other three protocols.Figure 12

Bottom Line: A beacon frame with the contained synchronous and poll information is designed to reduce the possibility of collisions of request frames.Dynamic time slot allocation mechanism is presented to manage the burst traffic and reduce the active period in each beacon period.The theory analysis is proceed and the result is evaluated in the hardware platform.

View Article: PubMed Central - PubMed

Affiliation: Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518005, China. zd.nie@siat.ac.cn.

ABSTRACT

Background: Human body communication (HBC) using the human body as the transmission medium, which has been regarded as one of the most promising short-range communications in wireless body area networks (WBAN). Compared to the traditional wireless networks, two challenges are existed in HBC based WBAN. (1) Its sensor nodes should be energy saving since it is inconvenient to replace or recharge the battery on these sensor nodes; (2) the coordinator should be able to react dynamically and rapidly to the burst traffic triggered by sensing events. Those burst traffic conditions include vital physical signal (electrocardiogram, electroencephalogram etc.) monitoring, human motion detection (fall detection, activity monitoring, gesture recognition, motion sensing etc.) and so on. To cope with aforementioned challenges, a statistical frame based TDMA (S-TDMA) protocol with multi-constrained (energy, delay, transmission efficiency and emergency management) service is proposed in this paper.

Methods: The scenarios where burst traffic is often triggered rapidly with low power consumption and low delay is handled in our proposed S-TDMA. A beacon frame with the contained synchronous and poll information is designed to reduce the possibility of collisions of request frames. A statistical frame which broadcasts the unified scheduling information is adopted to avoid packet collisions, idle listening and overhearing. Dynamic time slot allocation mechanism is presented to manage the burst traffic and reduce the active period in each beacon period. An emergency mechanism is proposed for vital signals to be transmitted. The theory analysis is proceed and the result is evaluated in the hardware platform.

Results: To verify its feasibility, S-TDMA was fully implemented on our independently-developed HBC platform where four sensor nodes and a coordinator are fastened on a human body. Experiment results show that S-TDMA costs 89.397 mJ every 20 s when the payload size is 122 bytes, 9.51% lower than Lightweight MAC (LMAC); the average data latency of S-TDMA is 6.3 ms, 7.02% lower than Preamble-based TDMA (PB-TDMA); the transmission efficiency of S-TDMA is 93.67%, 4.83% higher than IEEE 802.15.6 carrier sense multiple access/collision avoidance (CSMA/CA) protocol.

Conclusions: With respect to the challenges of HBC based WBANs, a novel S-TDMA protocol was proposed in this paper. Compared to the traditional protocols, the results demonstrate that S-TDMA successfully meets the delay and transmission efficiency requirements of HBC while keeping a low energy consumption. We also believe that our S-TDMA protocol will promote development of HBC in wearable applications.

No MeSH data available.


Related in: MedlinePlus