Electronic Drug Store Telemedicine and its application in telemedicine management.

152 CHAPTER 5 DEPLOYMENTS OF WIRELESS NETWORKS IN TELEMEDICINE From the previous chapter, it has been stated that patients’ med- ical records can be obtained from different channels according to the nature and format of these data. The information is also subject to different requirements prior to data transfer and utili- zation. Procedures to obtain the information have been dis- cussed along with their subsequent requirements for data transfer via e-health networks. The transfer of information such as patients’ vital signals and physical scans are different as they are subjected to different requirements. Numerous ways in ac- quiring data result in the estimation for both immediate and longer intervals in order to suit various health monitoring situa- tions. One of the main obligations is an effective and dependa- ble communicative channel to support patient caring. The establishment of channels is considered via the support of spe- cific applications to fulfil the specific requirements to comply with the nature and format of the data. As an example, the trans- fer of X-ray radiographies is subjected to distinctive procedures in the aspect of transmission capacity compared to the transfer of a text document that contains the information of treatment prescribed to patients. Each network possesses its own func- tional limitation on the capacity of information transferable in 153 both wired and wireless transmission. The channel transmission capacity determines the amount of transferable bits can be sent to another network per second. Therefore, a communication channel must be selected that can transfer the information and at the same time do not result in data overflow overflow of data happens when excessive of information is transferred to the same channel rapidly. To understand this situation let us take an example using the analogue network to send a HD video with a channel transmission capacity of 3100 Hz. Without doing any calculation, we obviously see that the capacity of trans- ferred data exceeds the transmission capacity. A MHz-capacity transmission capacity is still required to send HD videos even if the files are compressed. Information is obtained in the format of block or stream in digital networks. Due to the expansive na- ture of information, prediction cannot take place even in the case of random one-off measurement as there are no fixed pat- terns. Therefore in every data analysis, a discrete data block is received and additional data will not be accepted until the arri- val of next reading. The AE department is a very good exam- ple that shows randomized cases where at times it will be overflowed with patients and empty in others. Poisson distribu- tion modeling is the most effective model to manage the dis- crete likelihood in acquiring information Shmueli, 2005, lord et al 2010. On the other hand, a constant observation such as in gathering information of mobile healthcare devices results in a continuous influx of data. Hence, information is managed in a limitless time frame until monitoring is interrupted, such as the handling of audio and video information. To have a better un- derstanding on how discrete and continuous information are managed, we will examine the previous example of transferring HD videos. As the file is received in an influx in the time frame of five se- conds followed by no file transfer, the transfer of the total file can still be completed in a prolonged period as there is enough 154 time to process the data as in the situation of pouring a large amount of liquid down a funnel through a pipe with a narrow passage. It can still get through without spilling over if there is sufficient capacity in the funnel to buffer the flow before over- flow occurs. However, if the water keeps flowing in continuous- ly like a stream, it will not be able to get through. Imagine the consequences a tap is left on and causes water to flow continu- ously towards a narrow passage that could not retain the whole volume. Obviously, the water would spill from the funnel due to excessive water volume. The same concept can be applied in information transfer if too much data is transferred to a network without the sufficient transmission capacity to retain the data. Communicative channels are important in the current medical industry particularly in data sharing. From the previous chapters we have learnt that these channels were established with the main purpose of supporting a wide range of functions to support the extensive medical services. The following sections will show the methods to overcome the obstacles associated with network development and highly resilient channel equipped with the ability to incorporate new features made available from research. The knowledge obtained in Chapter 2 will be used to examine the basic mechanisms of channel planning and the re- quirements to future expansion. The major topics covered in- clude the outsourcing and its associated advantageous and disadvantageous and finally the quality assurance of network.

5.1 Strategies Involved in Network Deployment and Planning

In order to get a clear picture of the concept of the planning of telemedicine networks, the underlying concept must be under- stood. The most basic structure of network basically refers to peer-to-peer P2P framework as shown in Figure 5.1 which consists of two PC interrelated with each other. Each computer 155 is equipped with a network interface card NIC which provides them the capability to communicate with another PC. However, the intermediate mediums which use to connect both PC make are the same as long as data can be transferred between them. P2P’s main characteristic network there is no central region and all users other PCs have identical status. The overall picture of information sharing via Open Systems Interconnection OSI will be examined before proceeding to the mechanisms of communicative channels. Figure 5.1 Simplified P2P network the fundamental form of any network FONG et al 2011

5.1.1 The OSI Model

The OSI reference model equips a layout for channel interac- tions. The objective of this model is to standardize channel de- signs as a descriptive model for tiered interactions. For example, channel configuration is categorized into various tiers and with its own specific functions. Figure 5.2 shows the seven tiers consisted in the model. Every tier or layer is assigned to the handling of different tasks. Communication between any layer and the next is referred as direct. 156 Figure 5.2 Different layers in OSI model FONG et al 2011 This includes the exchanging of data blocks via a port of a layer called service access port. They are usually grouped into two categories, where the top 3 layers referred as host layers and transport layers for the bottom 3 layers out of the seven layers. From the literature, the middle layer is categorized into either host or transport layer. However, the name of this particular layer is called Transport, therefore it would be more logical to classify it into the layer of lower transports. Basically, the entire communication process is categorized into different functional areas by OSI model. The illustration of Figure 5.1 shows that the communication process of PC A is maintained with PC B. In a simpler sense, any layer of PC A talks to the layer of PC B can be referred to any layers in the OSI model. Any process car- ried out by a particular layer can be classified as its entity. Since there is no direct connection link between the two PCs, the communication between these 2 layers can be classified as vir- tual. Communication can be succeeded through the conversion be- tween Protocol Data Unit PDU. PDU is considered a shell that holds information identified as Service Data Unit SDU. 157 Hence, SDU is the entity of PDU that containing the header of data. The entity that belongs to any n layer is managed by n pro- tocol. These entities use the manage data in constructing SDU header to create a PDU that can be transferred to n - 1. The main objective of layer n is to receive the PDU from upper layer n + 1 and deliver to the subsequent layer below. If the size is not enough to carry the data, the segmentation and assembly process will be carried out to break the data blocks into smaller units at the sending end and reassembly at the receiver. Next, we take a look at the overall picture of the layers of OSI model beginning from the top: x Application Layer Application layer refers to the top layer among the 7 layers in OSI model. It takes establishes the communica- tion between users and the application of software. For example, when a staff wants to perform stock count, up- date of the database will be performed and any notifica- tion must be sent if there is any missing of stock. The staff enters the stock quantity into the system and the system updates the database. For any changes made to the stock count, system will auto-generate an email to the top management. All these processes are handled by application layers which include the database, email, browsers and so on. x Presentation Layer Presentation layer is known as a converter in the appli- cation layer for data from human users. Information is converted into appropriate code for system processing. Individual devices use different operating systems OS and hence different codes to present the information. Therefore, the presentation layer changes this infor- mation into a suitable format for data transfer. For ex- ample, smart phones and computer have different