Wireless Body Area Networks: Revolution to Medical Monitoring

Chapter 1

Introduction

1.1 Introduction to Wireless Body Area Networks (WBAN)

There are several challenges being faced when the human body is monitored within the medical health applications due to which a wireless sensing network is applied. The common concept of data acquisition is found when examining the human body within the studies of biomedical signals. Responses are given by a human body depending upon the scenario in which it is available. On the body of a patient, various sensors are deployed strategically such that all of the features can be monitored. Thus, a Wireless Body Area Network (WBAN) is generated through this. The functions of a body are monitored using a number of portable, autonomous, and miniaturized sensor nodes in WBAN. Within the natural physiological states, the health of patients is monitored without causing much affect on their normal actions through WBAN. The deployment of WBAN is done depending upon the radio frequency. Here, there is an interconnection amongst the small nodes of the network.

A radio frequency-based technology in which the small nodes are interconnected with each other using sensing unit or actuator capabilities is called WBAN. For providing support to several medical and non-medical applications, the nodes operate in close vicinity or within the human body. The physiological data is achieved from sensor nodes of WBAN with the help of medical bands. The interference is minimized and the coexistence of sensor nodes with other network devices that are deployed within the medical centers is increased by selecting an appropriate medical band. The medical gateway wireless boards are utilized by the multi-hopping approach for transmitting the collected data to remote stations. In medical science and human healthcare applications, the usage of WBAN has been appreciated at high level. Also within the biomedical and other scientific regions, a certain level of contribution is provided. Further, within non-medical areas like personal entertainment or clients electronic devices, these applications have been spreading on huge scale.

The WBAN architecture design consists of several devices/components. The important components are discussed below:

1. Sensor nodes: The base of any WBAN is generated through these sensor nodes. The physical parameters are monitored using several sensors deployed by these networks. In the close vicinity, or within the body, the sensor nodes perform operations. The bio signals are picked and forwarded to another unit for processing by these networks. There can be mono or multifunctional sensor nodes deployed in the networks. The implant nodes, body surface nodes and external nodes are three different types of nodes that exist in these networks.
2. Base Station: The data is forwarded, processed and analyzed using a local processing unit called the base station. Further, the patients are given output or feedback through the base station. To make sure that it is possible for the patients to take transmitter to their homes for easing their mobility, the separate base station is developed by most of the research applications of WBAN.
3. Central Server: A database is maintained within this unit. Proper medical guidance is provided by sending this collected data to a specialist.

There are certain requirements of WBAN in relevance to their design considerations. They are shown below:

• It is important to ensure that the sensors are small-sized and lightweight for making the devices non-invasive and unobtrusive in nature.
• Since the sensitive information of patients is gathered by the sensors deployed in the networks, it is important to ensure the WBAN are highly reliable.
• The robustness of system is important to be ensured.
• It is important to ensure that there is minimum latency due to which the overhead in the networks is negligible.
• With least power dissipation, there is a need to ensure that there is high energy efficiency for WBAN.
• The frequency and tissue warming have a direct relationship amongst each other. There is increase in the absorption of tissue with the increase in frequency of EM signals which also results in increment in the tissue warming. Communications require lower frequencies within these networks. However, the dimensions of antenna increase when the frequency is lowered. Thus, antenna dimensions and tissue warming have a correlation amongst each other.

1.2. Body Area Network

A technology through which the fitness and health of patients can be monitored and controlled through automated devices is called Body Area Network (BAN). Several low-powered devices known as sensor nodes are linked with each other and to a microcontroller unit (MCU) to perform certain emergency actions. To ensure that the important data is transmitted from one node to another radio transceivers are available in these networks instead of wired connections which speed up the performance. There are two methods in which the coordinator can function. Either the data is transmitted to a health care monitoring system through the gateway or the self-control hub is included that performs local monitoring. Wireless MCU has been designed lately to improve the performance of networks.

In case of external components, improvements are made by designing a single ship that includes both MCU and radio transceiver in it. Generally, when data is received from actual sensor devices, the sensor devices perform operations at a low-level interface where the MCU interfaces are loaded in return. All the important instructions within the actual sensor devices are included here. The radio chip available in MCU is used to transform raw data into logical information. The human body is wrapped up with wireless nodes in this process.

To examine the body functioning of an individual in various fields like in sports, in emergency health issues or in entertainment, WBAN is applied which deployed highly independent and portable sensor nodes. The bodies of patients are monitored in natural physiological states through this network and it also ensures that normal activities are not interrupted. In between the implanted devices and remote monitoring, communication is provided through WBANs. Even though these networks can be applied in different applications, mostly, medical applications include them.

For both medical and non-medical applications, low-power in body, as well as on-body wireless communication standards, are provided by IEEE 802.15.6. To perform wireless communications, several layers solution is provided for WBAN by the IEEE 1073.

For regular monitoring of patients such that efficient diagnosis and perceptions can be achieved, it is important to consider both in-body and on-body monitoring of patients through WBAN. In multimedia and gaming applications, it is possible to include on-body sensors. Emergency, Normal traffic and on-demand are the three different kinds of traffics generated in WBAN technology. During diagnosis, it is necessary to find out particular kind of information which results in providing on-demand traffic which can be either discontinuous or continuous. When exceeding the predefined threshold, the nodes are known to include emergency traffic and in the time frame for one second, they should be accessed. This kind of data is highly unpredictable and is not generated regularly. The data traffic is considered to be generating normal traffic in case when there are no time-critical or on-demand events included. It is possible to monitor the health of patients and provide them proper treatments through these network applications. The coordinator is responsible in collecting and processing the normal data collected all across the network.

1.3 Standards of WBAN

WBAN includes several standards that help in performing communication. These standards are used to generate wearable devices that are based on microchips. The most importantly used standards are explained below:

1. Bluetooth: IEEE 802.15.1 standard is used in Bluetooth where in 10m range, short-range communications are performed. The Bluetooth device has 3 Mbps of data rate. Higher bandwidth and lower latency are the two important features of Bluetooth.
2. ZigBee: Along with collision avoidance technique, this standard is applied that helps in controlling communication-based highly complex operations. Only about 60mW of energy is consumed by the communications performed here and 250 kbps of data rate is provided. To ensure security in systems, encryption can also be provided through this technology.
3. MICS: To perform communication across medical fields, the MICS standard is designed that provides both on-body and on-body communications. Short-range communications particularly for body-range communications are performed through this technology. In comparison to the ultra wide band, less power is consumed by this method. Thus, very less energy is radiated out here and the human tissues are not harmed through the rays emitted.
4. Ultra Wide Band: Another standard for WBAN that is used in high data rate applications is ultra-wide band. This is the best option for applications that have high bandwidths. Results for emergency applications are provided by this technology that also includes GPS in it. The complexity of GPS receiver is high due to which the wearable applications use it.

1.3.1 Types of Nodes in WBAN

An independent device that includes the capabilities of communication device is a node that is deployed in WBAN. There are three categories in which the nodes can be categorized:

• Functionality
• Implementation
• Role

Following are the categories among which the functionality of WBAN nodes can be divided:

1. Personal Device: A device that is chargeable and is responsible for collecting the information being received from sensors and actuators is called a personal device. The interaction among other users is being handled through this device. The information can be displayed such that is can be passed on to the users using the external gateways which are also called as body control units, gateway and sinks.
2. Sensor: Both internal and external parameters are maintained by the sensors deployed in WBANs. A physical stimulus is used to collect the information and generate response across these nodes. They are physiological, ambient and biokinetic. To monitor all the surrounding regions, the wristwatches, mobile and earphones etc. can include these sensors.
3. Actuator: For receiving information and data across sensors, the actuators interact with users. Providing valuable information is the most important role here. For health care applications, pumping dose of medicine is the best example.

An implementation part is included after functionality. There are certain components included here which are:

• Implant node: The human body includes such kind of node. There are two different methods which are below the sink or below the skin tissue to implant the nodes for such networks.
• Body Surface node: Either on the surface of human body or 2cms away from the body skin the body surface node is placed.
• External Node: Both underneath and inside the skin, the nodes are not available and they have no direct contact with human body.
• Based on their roles, the nodes are classified as:
• Coordinator: For the external world or other WBANs, an access coordinator is provided by deploying a coordinator node.
• End nodes: The performance of end nodes deployed in WBAN is limited and in the embedded applications, they are used. However, relaying the messages from other nodes is not possible here.

a.Mobility-supporting Adaptive Threshold-based Thermal-aware Energy-efficient Multi-hop protocol (M-ATTEMPT): A human sink is included in these protocols where the high data rate nodes are deployed. In case of availability of low data rates, the nodes are deployed far from the sink. There are different phases on which the protocol operation can be applied. In the initial phase, hello messages are broadcasted. In terms of hop count, the information is collected from the neighbors and sink nodes. To transmit the data from nodes to sink, the routes with minimum hops are chosen in the routing phase. The routes that have minimum hop counts are chosen here. Towards the closest high-data-rate nodes which forward the data to the sink, the data is transmitted by the low-data-rate nodes. The lifetime of networks is improved in this protocol through single-hop and multi-hop communications. Once the route is selected, TDMA slots are assigned to the nodes. Depending upon the data rates, the characterization of nodes can be done into three different phases:

• Parent Nodes
• First Level Child Nodes
• Second Level Child Nodes

For saving energy, the child node gets associated with other closest parent node when the human body is mobile and the child node is distant from parent node. If the nodes heat up to an exceeding level the hot-spot scenario occurs.

b. Stable Increased Throughput Multi-hop protocol for Link Efficiency (SIMPLE): At different locations within a human body, eight nodes are deployed through this protocol. At the waist, a sink is deployed. There are different phases in which this protocol performs tasks. For knowing the position of sink on human body, the short-length information packet is broadcasted to the sink in the initial phase. A node ID, residual energy value and its location are known for every node. To route the data of other nodes by saving energy, a forward node is chosen in the next phase. Depending upon the distance from sink and residual energy of any node, the sink is chosen. The node that has least distance from sink and the highest amount of residual energy value is chosen here. To aggregate the received data and route it towards the sink, all the corresponding nodes forward the data to the forwarded node. The TDMA slots are used for the child nodes.

c. Forwarding Data Energy Efficiently with Load Balancing (FEEL): The stability period and throughput of nodes are improved by applying this protocol. On the human body, eight numbers of nodes are deployed. The ENG is monitored by node 8 and glucose level sensor by node 7. To deploy sink, mainly two different kinds of topologies are used. The sink is deployed on the chest in the initial type. The sink is deployed on the wrist in case of second topology. To initialize the first phase, HELLO messages are broadcasted. Three different kinds of information are included in these messages:

• Sink’s Location
• Neighbor’s Location
• Information Related to the Possible Routes to the Sink.

The HELLO messages are received by the nodes and routing table is updated in the final step.

1.4 WBAN Applications

WBANs are deployed within several application areas today due to the several advantages they provide. It is possible to provide remote monitoring of data, provide interface for diagnostics, and provide health treatment in hospitals with the help of W-Health Care BANs. The continuous monitoring of patients and providing them the appropriate medication is possible through these applications. For monitoring purposes, there is no need for the patients to be connected to larger technologies anymore. Some of the most commonly found applications that deploy WBAN are elaborated below:

a. Military Applications

For sensing and confining fleeting signals from several huge weapons, experiments are conducted using auditory sensor arrays that hang below tethered aerostats by the Army Research Laboratory (ARL). The survival and lethality of soldiers is affected due to the unrelenting inspection. Within flattering MET circumstances a huge range of detections is provided similar to an array. There are several opportunities in which BANs can be applied in these fields.

b. WBAN for Animals

It is also possible for WBANs to detect and improve health conditions within animals by recognizing various infectious diseases. It is very important to improve the health of animals and control the diseases in them for improving the health of humans since several food sources are achieved from animals. The humans and animals are interdependent on each other and have a symbiotic relationship due to which it is important to handle the health-related issues of both of these categories.

c. Networking and communications

It is possible to integrate Internet and other networks by deploying WBAN. Thus, highly secure wireless communication system is generated in which the operations and cost are minimized by reducing the numbers of resources needed. When performing communications within harsh scenarios, cognitive radio plays an important role. The performance of these networks is challenged due to certain factors that are possible because of the harsh environment available in surroundings.

1.4.1 Issues of Secure and Reliable communication in WBAN

WBAN faces several issues when providing secure and reliable communication amongst which few are presented below:

• Data Confidentiality: Since the traffic can eavesdrop on the traffic and receptive information can be accessed on the user, secure data transfer mechanisms are required within WBAN applications.
• Data Authentication: The contribution within the network is needed only by the legal nodes of WBAN. The reliability of received message is ensured through data authentication. For authenticating that information is surely sent to sender, data authentication agrees to the receiver.
• Data Integrity: The message can possibly be extracted by the rivalry when the information is transferred from an approved sender.
• Data Freshness: The information being received needs to be ensured is latest due to which its freshness is calculated.
• Location privacy: A person can be identified uniquely with the help of communication amongst the nodes since the nodes in WBAN are deployed over the human body. Thus, inherent Location privacy risks are bounded to be available within the WBAN applications.
• Contextual privacy: A co-relation with the source and destination is required by an adversary when breaching the contextual privacy. The context of sensitive information is achieved through this.
• Access Control: The data can be transmitted and received from WBAN network by several users. The private information is important to be protected from unauthorized users.
• Non-repudiation: When the responsibility of sending or receiving the messages is denied, repudiation threat is caused which is important to be avoided within these networks to ensure security.

1.5 Disruption Tolerant Networks (DTNs)

Interplanetary communication was the base on which the concept of Delay or Disruption Tolerant Networks (DTNs) originated. A continuous end-to-end link was assumed to exist amongst the distant devices and local control center when providing communication to distance satellites. Amongst two communication partners, common occasional links exist which result in huge disruptions and thus longer delays within the complete chain of communication. There are some traditional protocols such as TCP or UDP which are applied for communication. However, higher delays and disruptions cannot be handled by these protocols since the permanent and stable end-to-end topologies that are not available within outer space are a major factor on which they depend. However, reliable and secure communication is provided by DTN protocols which are proposed lately by researchers. Amongst two communication partners dependable hop-by-hop communication is established when there is a physical radio link present amongst any two partners.

The data is stored, carried and forwarded by node M in a DTN node. Amongst the communication range of each other it is not possible to use common protocols. The data is forwarded by node A to moving node M within a DTN. The data is then stored and further transmitted physically within the communication range of node B by node M. The data is forwarded by node M to be node B once it arrives. For DTNs, the standardized protocol named Bundle Protocol (BP) is applied.

The transmission of data is done wirelessly to the sink within several wireless monitoring environments. There are however, several different challenges being faced within the WBAN scenarios. It is not possible to assume any continuous end-to-end connection between the data capturing BAN in case of any human activity monitoring environments. In most of the scenarios, it is not possible to predict the mobility of humans unlike the mobility of large satellites and probes which can be calculated. It is possible to modify the data rate of wireless channel, in the first scenario, due to packet collisions, shadowing and other physical influences within the steady wireless links. Secondly, there is a complete collapse in data transmission when the person being monitored is out of the communication range of sink. The quality of data will degrade in the initial scenario and there will be loss of data in the second scenario. Since the monitored person is completely out of the range, the complete field study might get jeopardize. Only an appropriate dimensioned communication protocol can handle this type of scenario.

Chapter 2

Literature Survey

This research work is related to data prioritization which is transmitted in wireless body area network. The wireless body area network can be sensed by the sensors which are used to sense different body conditions. The techniques which are proposed by the various authors for data prioritization, data routing and related to increase lifetime are presented in this chapter

2.1. Data Prioritization Techniques

Ambigavathi.M et.al (2018) presented a new scheme for the transmission of critical data by ensuring the least delay in networks. This approach uses the IEEE 802.15.6 standard for developing Energy Efficient and Load Balanced Priority Queue Algorithm (ELBPQA). As per the location, the packet obtained from the personalized device was classified primarily. The scheduling was done on the basis of data priority due to the local generation of packet. The packet will be scheduled on the basis of deadlines if the packet is received from remote area. High, medium and low priority, are the three different levels in which priority is provided. The hardware scheduler is used to schedule and transmit the data on the basis of priority. It was seen through the evaluations that the performance of propose research algorithm was better in terms of several parameters.

Ping Zhang et.al (2018) proposed Multi-functional secure Data Aggregation scheme (MODA). This technique was proposed to encode raw data into well-defined usable form and perform some specific task like value-preservation, order-preservation and context-preservation and also perform a special function of building the infrastructure for data aggregation. In this research, the author specifically used homomorphic scheme to work on cipher text aggregation and end-to-end security. In this study, Random selected encryption Data Aggregation (RODA) and Compression based Data Aggregation (CODA) were two newly approaches. These approaches were considered as advanced and developed techniques. The function of RODA was to decrease communication cost at the margin of lesser and extra security on the leaf node where as the purpose of CODA was the decrease in communication cost by lowering the rate of accuracy. The researcher concluded from the obtained results that the superior performance results could be achieved by proposed approach in comparison with other existing approaches.

Ashwini Umare, et.al (2018) introduced a novel routing protocol based on cluster for Wireless Body Area Networks. The Genetic Algorithm was utilized for the optimization of proposed approach. Darwinian Principle of Natural Selection was the inspiration of Genetic Algorithm. Genetics proved one of the most significant optimization methods. The proposed GA-based scheme for WBANs produces much-improved outcomes were produced by the introduced approach in comparison with other existing protocols in terms of several factors such as life span of network, formation of cluster head, power exhaustion and network throughput. The proposed approach may be modified in future through the consideration of different body positions. In future, the security system can be applied for ensuring safe data transferring.

Srinivas Doddipalli, et.al (2018) presented a planar Ultra Wide Band (UWB) antenna with a slotted substrate for WBAN applications. This antenna is constructed with an advanced elliptical-shaped radiator was utilized for the construction of this antenna. In this antenna, slots on the patch surface and a curved shape imperfect ground plane with adapted substrate shape were etched. At higher frequencies, the return loss performance was improved by new substrate arrangement. The proposed antenna occupies the minimal area was occupied by the proposed antenna which was 646.88mm2. The wide frequency range from 2.94 GHz to 17.6 GHz was covered by the proposed antenna in comparison with other existing structures. For achieving improved performance characteristics, the effect of different slots and design parameters was scrutinized. In the fabrication tolerance, the architecture was good. This design showed total bandwidth of 14.66 GHz.

Thanadol Tiengthong, et.al (2018) investigated the assessment of power delay feature of UWB transmission waveform for WBAN with human corpse. The investigational model, VNA and biconical antennas were utilized for investigation. At the receiver end, the delay feature of transmission waveform was evaluated using expansion of friis’ transmission formula, rectangular passband waveform and power delay report. The investigational outcomes demonstrated power delay profile. These outcomes depicted the effect of UWB transmission waveform on human body. The UWB transmission affected the human body in terms of reflection and shadowing. The postures of the human body will be taken into account in near future.

Abhilash Hegde, et.al (2017) presented a concise review on inferior layers of WBAN system with the help of a simulation tool called Castalia. The results achieved from approach evaluated the requirement for WSNs over wired networks. These results also provided necessary outcomes for the utilization of WBAN in health applications efficiently. In WBANs, the proposed approach also provided quality of service with energy restriction in sensors. This phenomenon assisted in the deployment of several equipments with inexpensiveness and high competence.

Charinsak Saetiaw, et.al (2017) presented the architecture of a capsule-shaped patch antenna. This antenna was implemented on fabric substrate for WBAN applications at 2.45GHz ISM band. For ground and radiator layers, and denim as a dielectric substrate, the proposed design utilized Pure Copper Polyester Taffeta Fabric in the form of conductive substrate. Usually, a fundamental rectangular antenna had a narrow bandwidth. In this study, a novel design was proposed. In this design, a rectangular shape was combined with a half circular shape at both ends. This antenna was called a capsule-shaped antenna. One more aim of this investigation was to propose an antenna that could be established directly on cloth for a small sensor WBAN. The factors utilized for scrutiny were dependent on resonance frequency. On the basis of reflection coefficients, the frequency of operation could be scrutinized as per the achieved from simulation outcomes. In this study, some patterns of antenna had been constructed and calculated. The tested outcomes depicted that 5.63dB and 3.53dB was the antenna gain obtained from simulation and computation correspondingly. Lastly, the measurement outcomes were utilized for the verification of radiation pattern of proposed antenna.

Da-Ren Chen et.al (2017) studied the issues of 2-covered path. These paths had antennas and separate transmission power level values had been showed by these antennas. Three power-aware methods were proposed in this study for the framing of 2-covered paths linking source with the sink. These techniques were based on graph transmission planning (GTP), which was implemented on various strategies to decrease the energy consumption value of the network. Various experiments were conducted to prove the theoretical results. These results showed that about 96% of the total network’s energy was consumed by proposed approach. The better performance was shown by proposed approach in comparison with existing methods as per the amount of energy being conserved, apart from the density of the antenna, quantity of antennas and the radii of the antennas. The execution time of proposed approach was extremely less as compared to the other methods.

Anees Ara (2017) proposed a novel approach called Secure Privacy-Preserving Data Aggregation (SPPDA). The bilinear pairing for distant health observing systems was the base of this approach. This approach was applied to improve the effectiveness of data aggregation and data confidentiality. In this respective approach, homomorphic scheme was employed in order to have much more effective results. Homomorphic scheme was used for performing privacy-preserving secure calculation and then collaborated with aggregate scheme. This scheme was proven to be one of the most secure schemes under the Decisional Bilinear Diffie-Hellman (DBDH) supposition. The proposed technique can possibly preserves data confidentiality and data privacy and most importantly prevent harmful eavesdropping and malicious attacks in the network. The results of the research concluded that proposed technique was less expensive, reduces the communication cost and supports the computational services at the remote servers.

Xiong Li et.al (2017) proposed an enhanced single-round authentication protocol. This protocol successfully overcomes all the drawback of the previous work has been done on this field. The recognized and unrecognized safety concerns of this protocol were reviewed in this study. A comparative analysis demonstrated that the proposed protocol effectively improved safety with the corresponding cost. The proposed protocol also achieved more security characteristics and functions in the very same cost. In this study, light weighted authentication protocol had been framed for wireless body area networks having three tiers along with the wearable devices. The researcher concluded that the WBAN can be used in various applications like data aggregation and medical big data protocol with secured data protection.

Amit Samanta (2017) proposed a novel network management cost minimization structure for optimizing the throughput and QoS of every WBAN. This protocol effectively minimized the active connectivity; disturbance manages various types of disturbances being created in the network and managed the cost of data broadcast. The researcher theoretically observed that proposed framework provided a reliable data transmission in opportunistic WBANs. Different simulations results demonstrated impressive enhancement in the performance of the introduced protocol in comparison with other earlier protocols. A new network management was proposed to manage the cost of the network. The interaction between the intra-BAN and inter-BAN communication was reduced through the occurrence of dynamic postural disconnections. The cost of network management and the life-time of the sensor node were directly affected by this phenomenon. It was analyzed that the projected protocol successfully decreased the cost of network management and also managed the lifetime of the network.

2.2. Data Routing Techniques

Yu Zhang et.al (2017) proposed a novel relay-aided transmission power control method. This method provides dependent transmission and also had the ability to lessen the burden on relay node. This technique had the ability to switch transmission strategy of transmitter along with the direct transmission and relay-aided transmission according to the conditions of channels that addressed the long-distance crisis. This had the tendency to adjust the transmission power required at the time of working of network based on the received signal strength indicator (RSSI). The trustworthy transmission and preservation of the energy of relay nodes had been guaranteed by RSSI in the most possible way. Moreover, this protocol could be transformed according to the application environments for exchange among trustworthiness and power effectiveness. The simulations and experimental outcomes concluded that the transmission trustworthiness and power consumption of relay node had been provided by the proposed method in an effective way and this consecutively increased the lifespan of network.

Ms. I.Shanmugapriya et.al (2017) discussed about the various issues WBAN facing. Secure communication over wireless body area network (WBAN) was one of the major and frequent challenges being faced by WBAN. This is due to the lack of security and privacy level at the time of data transmission. In order to overcome these issues wireless body area network Repute Derivative Incentive and Sparse Sampled Data Aggregation (RDI-SSDA) scheme was proposed. the proposed scheme initially use Repute Derivation Based Incentives scheme to detect the genuine network users on the certain interval of time by making use of second order derivative for the transmission of data and enhanced throughput. In this paper, the researcher discussed about the maximum delay packet. This selects data packets having minimized tolerance delay for collecting data and hence improves the data aggregation efficiency. Compressed sensing was performed for every aggregated data by sensing matrix in which encryption and decryption was done to enhance the privacy of data transmission wireless body area network. Various experiments were performed in order to verify the theoretical results. These results concluded that proposed approach works in parameters like data privacy level, throughput and data aggregation efficiency. The researchers also concluded the proposed approach improves the privacy level of data and data aggregation efficiency in comparison to the other techniques.

Vandana Jayaraj, et.al (2016) proposed a novel topology for addressing several issues related to effective data transferring. The proposed topology allowed the formation of virtual groups between sensor nodes and mobile equipments of patients, nurses and doctors for performing distant study of WBAN records. Through the appropriate up gradation of patient's data, group formation was performed for temperature, ECG, EEG, heart rate etc. With the help of an underlying environmental sensor network, the collected WBAN data was forwarded to the members of practical group. This data would be sent and receive by the virtual members for a specific time period with the help of network protocols. The monitoring of serious patients became easy for doctors by providing them early help, stopping life-loss because of transmission delay. With the help of network simulator, a series of simulation was utilized for the evaluation of presented scheme.

Rae Hyun Kim, et.al (2016) proposed a novel MAC protocol in form of TDMA based method in CSMA/CA atmosphere. The maximum delay limit to every type of data packet was applied by proposed approach for dealing with delayed packet. This limit was applied due to the collision in data transferring when two or more packets were transmitted in the similar time frame. As per the disparity of overall presented data traffic, the packet delay was compared with the random selection-based approach. The result of packet delay was scrutinized in terms of delay obligation. The cooperation of proposed approach was required with high and varied data traffic in upcoming WBAN-based scenario.

Hamed Mosavat-Jahromi et.al (2016) investigated the spectral effectiveness of a communication connection in a wireless body area network. This scheme was able to harvest power from the surroundings. In this paper two situations were considered namely, single and dual hop and power management task was successfully achieved by each of the scenarios. The objective of the first type of scenario was to maximize the link’s spectral efficiency, monitors the battery capacity, monitors energy harvesting constraint and overcome all the drawbacks of the WBAN which includes the issues of power and outage probability. The aim of the second scenario was to decode and forward the relay node and optimizes the spectral efficiency issues. Moreover, the researcher also introduced channel distribution information (CDI) at the transmitters, the lower and upper bounds of the average spectral efficiency are also derived in both scenarios. The results of the research concluded the performance of the proposed protocol was quite satisfactory in comparison to the other techniques.

Rim Negra et.al (2016) presented different medical applications. The researchers highlighted the use of developed and advanced technology of the WBAN. Matching between the each applications and the technology corresponded to this had been studied and analyzed. The main objective was to provide appropriate and suitable wireless techniques for every network in order to achieve this; details of every developed technique had been presented. The researcher successfully discovered the radio technology for WBANs and tried to meet all the demands and requirement of WBAN applications. In this paper, the type of infrastructure of WBAN was also proposed. The intra-BAN communications between body sensors and master node had been comprised by this architecture. These communications included energy, latency and throughput values. This architecture had intra-BAN interaction amid the master node and more than one access points. The collision and intrusions took place on the entire shared channel. The wireless technologies for inter-BAN communication had been comprised by this architecture. These technologies included WLAN, Bluetooth and a lot more wireless appliances. Apart from BAN communications which enable the authorized healthcare personnel in order to remotely access patient’s medical information with the help of cellular network or the internet.

Un-Ha Kim et.al (2016) analyzed the delay in packet collection for multisource sensor data along with an on-off traffic pattern in WBANs. Two functional parameters were taken into account in this study and calculated the probability of packet gathering occurrence in per unit time. In this study, the delay in standard gathering delay was derived in a closed-format. The scrutiny outcomes revealed that an increase in aggregation delay was seen along with the increase of aggregation timer or aggregation threshold. According to the amount of active sensors and their on-off traffic qualities, it was delimited below definite level. Therefore, the aggregation of data increased the effectiveness of data transferring during the satisfaction of delay requirement in the WBAN network. The delay necessities of applications were satisfied by two factors i.e. aggregation threshold and aggregation timer. The theoretical basis required for getting optimum functional parameters could be provided through proposed approach. This increased transferring effectiveness and ensured delay restraint of WBAN application. Therefore, it was analyzed that delay and structure were occurred for other data aggregation systems similar to intra car sensor networks, wireless sensor networks, mission critical sensor networks etc.

Amandeep Singh (2016) proposed TDMA approach to avoid packet collision. The clock synchronization was the most appropriate solution for packet collision. When the clock was synchronized, then data could be forwarded efficiently. A network having special feature of sensing of human body conditions was identified as wireless body area network. This network was the advanced and improved version of wireless sensor network. This network was organized with fewer number of sensor nodes. It only comprised of maximum seven sensors and all these sensors were of low range and this was the second improvement in terms of the range. This technique was called channel sensing method. A direct path from source node to the transferring node was provided by routing protocols. This network had various source nodes and just one target node. Therefore, proposed technique effectively avoided packet collision.

GuangXia Xu et.al (2016) proposed a novel data privacy protective mechanism for WBAN. The proposed approach combined symmetric key and asymmetric key for safe transmission of client’s data. For better capturing of defense and the attacks of nodes, the data was cut and reorganized during transferring procedure. Eventually, the data of client was transmitted safely by considering that the data gathered by nodes was not to be disclosed and safe as well. The proposed approach utilized some technologies such as the combination of established encryption arithmetic, hash arithmetic and the cutting and rearranging of data for ensuring the privacy and reliability of the parameter information, fault tolerance and sturdiness of network. Up to now, several studies on WBAN were mostly based on the structural design but confidentiality and safety were also important the issues of WBAN system due to the significance of message transmission in WBAN. Thus, the proposed approach had definite functional significance.

2.3. Energy Efficient Techniques

Nourchène Bradai et.al (2015) considered bridging communications between WBANs and centralized public-BAN (WLAN). In order to persuade the requirement of the quality of service in WBAN and overcoming the starvation mode of the packets with no higher precedence, two novel algorithms were proposed in this study. Critical display parameter was introduced to perform this task. This parameter was used to serve packets by the priorities and classification of a combined structure. The Priority Queue scheduler (PQ) and Priority Queue Aggregation scheduler (PQA) were used to perform comparative analysis with proposed approach. The simulations and experiments were conducted to prove the theoretical result which demonstrated the performance of this approach and removed all limitations of further schedulers in terms of some factors. These factors included latency, throughput, dropped packets, observation and scheming of load traffics.

Wei Quan et.al (2015) presents a novel Information-centric data retrieval approach in WBAN. This mechanism was called IWBAN. The main aim of the proposed approach was to improve trustworthiness and effectiveness. The proposed approach had various features i.e. (i) in place of address-based delivery implementation of name-based delivery; (ii) utilization of copy of caching contents in place of unnecessary sensors; (iii) in place of the sender-driven transferring utilization of receiver-driven chunk-level data transferring. Various simulations were performed to prove the practical results. As per the simulations results, it was analyzed that proposed approach showed satisfactory progress in terms of packet loss ratio, transferring delay and power utilization with the help of 6LoWPAN. According to this, the performance of the I-WBAN was explored in terms of the packet loss rate, transmission delay and energy consumption. Thus, it was concluded that the proposed approach could decrease power utilization rate and improve the lifetime of network.

Song Han et.al (2015) proposed a novel approach called privacy-preserving and multifunctional health data aggregation (PPM-HDA). The proposed approach was applied with fault tolerance for cloud-supported WBANs. The multiple statistical functions of clients’ health-related records were computed by proposed approach in a much secured manner. Especially, in this paper the researcher proposed one more approach which was called multifunctional health data additive aggregation scheme (MHDA ). This approach supported the preservative aggregated purposes like average and variance. After, this the researcher moved forward by extending the work of the proposed technique to support the non-additive aggregations like min/ max median, percentage and histogram. This technique had the ability to prevent all the attacks by which the data aggregation was mostly suffering from. The researcher concluded that the proposed approach successfully protected the data of user against May threats. The energy efficiency was reduced in terms of communication overhead as per the obtained outcomes. This happened due to the requirement of huge plaintext space and extremely-precise records by some the applications.

Ilkyu Ha, (2015) investigated the various properties of WBAN that make them distinguishable from other networks. Also, to improve the efficiency of WBANs, different improvements required in these networks are studied. The systematic literature review (SLR) approach is applied for investigating the different trends of WBANs. The different researchers and their fields are classified as per the investigation. The presentation of survey results is done here and the summarization of studies is done for performing an outlook on them. Different research trends required in WBAN were recognized through this investigation with the help of which further improvements in this technology were suggested.

Sudip Misra et.al (2014) proposed a novel approach called Body Area Network Data Aggregation Algorithm. A priority order for every patient was created by this approach on the basis of adversity and seriousness of the health of patient. The health severity of each patient was measured by an exigency feature. By considering Theory of Social Choice, a pseudo-cluster-based fair aggregation approach was presented as well. The proffered and amassed health data was channelized through Cloud gateways. With the help of Optimal Channelization Algorithm, this data was channelized in an extreme synchronized way. The tested outcomes depicted that projected approach was better in some parameters as compared to existing approach such as the trustworthiness of node selection, quantity of packets conveyed, superfluous broadcasting and jamming possibility. The existing approaches were identified as structure-less and tree-based aggregation practices. The achieved outcome illustrated about the selection of data packets for their transmission on cloud. This choice was biased and synchronized towards gateway capability and reduced communication expense.