RESEARCH MODEL

The research model (see Figure X) including the independent and dependent variables is depicted in Figure 25. The independent and dependent variables are explained in the following sections.

DR = Device Range, NHP = Number of Hops, ODD = Overall Device Density, CLD = Clustered Distribution of Patients, UND = Uniform Distribution of Patients, TP = Power Transmitted by the PMDs at each hop, VSC = Variation in Size of Clusters, VNC = Variation in Number of Clusters, CL ON/OFF = Clusters on/off the route of transmission, P-VS = Patient’s Vital Sign (Emergency/Routine), SU = System Utilization, SR = Service Rate of the PMDs involved in End to End Signal Transmission, E-E PT = End to End Power Transmitted, E-E RL = End to End Reliability of Transmission, E-E DL = End to End Delays in Signal Transmission

The following tables (i.e. Tables 9, 10, and 11) provide a brief description of the constructs, independent, and dependent variables considered in the current research.

Table 9: Key Constructs in the Current Research

CONSTRUCT DEFINITION COMMENT

Source Patient device initiating signal

transmission The patient device transmits the signal via ad hoc wireless network formed among patient monitoring devices (nodes) Destination A Healthcare professional. The signal is transmitted from

source to destination via a pure multi-hop MANET

End to End Signal Transmission

Transmission of signal from the source to destination via a multi-hop MANET

Table 10: Independent Variables in the Current Research

INDEPENDENT VARIABLE DEFINITION COMMENT

Transmitted Power Power transmitted by each PMD at each hop in the end to end signal transmission

Transmitted power impacts device range at each hop which in turn impacts the number of end to end hops in signal transmission.

Device Range The range of the

transmitting PMD which is dependent on transmitted power at each hop.

Device range defines various possible scenarios pertaining to transmission range of the PMDs forming a MANET for signal transmission

Number of End to End Hops Total number of hops in end

Uniform Device Distribution PMDs distributed uniformly

in the area of transmission Impacts overall device density in the transmission area

Clustered Device Distribution Patient mobility resulting in non-uniform distribution of PMDs in the area of transmission

Impacts overall device density in the transmission area

Variation in Size of Clusters The clusters vary in size (i.e. the number of PMDs forming the cluster)

Impacts overall device density and the density of the clusters. Overall device density decreases as the size of cluster increases.

Variation in Number of

Clusters The clusters can vary in number (i.e. the number of clusters in the area of transmission)

Impacts overall device density and the density of the clusters. Overall device density decreases as the number of cluster increases. Clusters On/Off the Route of

Transmission Clusters can be on route and off route of end to end signal transmission

Impacts end to end power transmitted, end to end reliability, and delays

Overall Device Density/

Overall Network Density The density of PMDs in the area of transmission, some or all of which can route/transmit signal via a multi-hop MANET

Key variable that defines multiple patient monitoring scenarios pertaining to transmission at various device densities

Patient’s Vital Sign Patient’s vital sign warranting transmission can be emergency or routine

Variable impacting the constraints with respect to delay tolerance and the choice of PRD protocol for end to end transmission

System Utilization System utilization defines the transmission load on the system.

Higher the system utilization higher is the end to end delay in signal transmission

Service Rate Service rate is specific to the PMD and defines the rate at which a signal is processed by a PMD

Higher the service rate lower is the end to end delay in signal transmission

Table 11: The Dependent Variables Considered in the Current Research

DEPENDENT VARIABLE DEFINITION COMMENT

End to End Power

Transmitted Total power consumed in end to end signal transmission via a multi-hop MANET

The objective is to optimize/minimize power end to end power usage

End to End Reliability Reliability in end to end signal transmission expressed in terms of probability of locating cooperative PMDs at each hop in end to end transmission

The objective is to maximize reliability. Reliability always takes high priority in the context of patient monitoring even if it is at the cost of power usage and delays

End to End Delays Total delays in end to end signal

transmission. The objective is to predict delays in end to end signal transmission via the PRD protocols under diverse patient monitoring scenarios

Objective of Performance Evaluation and the Corresponding Plan

A. Objective of performance evaluation with respect to the PRD protocols:

The PRD protocols seek to utilize variable-rate transmit power by the source and the intermediate routing devices. The desired outcome of utilizing PRD protocols for end to end signal transmission under diverse patient monitoring scenarios are: (a) enhanced reliability, and (b) prediction of power consumption and delays. The anticipated result is maximization of end to end reliability at variable levels of power consumption and delays corresponding to each PRD protocol. Hence the performance evaluation of the PRD protocols is associated with the protocols achieving the anticipated outcome under diverse patient monitoring scenarios.

An overview of the performance evaluation plan with respect to PRD protocols is presented in Table 12. The performance of the key variables (end to end reliability, end to end power, and end to end delays) is measured and recorded under diverse scenarios with and without

utilizing PRD protocols.

Table 12: Evaluation Plan of the PRD Protocols – Measuring Performance of E-E Reliability, E-E Power Usage, and E-E Delays in Signal Transmission

Overall Device Density

Uniform Device Distribution Clustered Device Distribution Variations in Transmitted

Power Level With/Without Utilizing PRD Protocols

No Clusters Variation in Size and Variation in Number

Without Utilizing PRD Protocols – Variations in Fixed-Rate Transmitted Power Resulting in Variations in the Number of End to End Hops.

E-E Power Usage E-E Reliability E-E Delays

E-E Power Usage E-E Reliability E-E Delays

With Utilizing PRD Protocols in End to End Signal Transmission:

RP-RCD, MP-MCD