# Telemedicine: A Survey of Telecommunication Technologies, Developments, and Challenges
## 2 Related Work
[30] highlighted several major issues in the implementation of wireless sensor network in telemedicine. In particular, issues related to ZigBee and Bluetooth transmission technologies used for communication between sensors and WSN were emphasized. In their survey article, Ref. [31] specifically discussed mobile telemedicine systems using satellite-based communication and cellular technologies. In another article [16], the research was focused on wireless technologies and the challenges to e-health. Similarly, Ref. [32] provided useful insights on wireless technology and the challenges present in telemedicine. Their work presented more details on the application of wireless technologies in healthcare as well as challenges with wireless telemedicine, mobile phone telemedicine, and data transmission techniques. In [33], the authors presented an article on wireless telemedicine localized in Tanzania. The authors provided a description of different wireless technologies used in telemedicine. Body Area Networks (BAN) for monitoring of patients in telemedicine were considered in [4]. This study posits that telemedicine can leverage the advancement of microelectronic technology for healthcare delivery. Specifically, their paper discusses the integration of BAN in telemedicine systems involving a Wide-Body Area Network (WBAN) framework. A review of devices used in telemedicine systems was showcased in [34]. Primarily, the authors showed the devices for obtaining the vital signs for telemedicine applications; more precisely, the integration of vital sign sensors and other wireless medical devices to telemedicine systems were highlighted. In [35], the authors showed how an ad hoc wireless sensor network system could be applied in the telemedicine sub-area of disaster survivor detection. Relay stations were deployed to transmit captured data to sink nodes, which then forwarded the data to either the base stations of a cellular network or to WIMAX-based antennas. In [31], the authors reported that mobile communication technologies for telemedicine must have operational parameters that meet the expected Quality of Service requirements of medical services, which can include clinical data measurement of images such as digital X-Rays and audio signals with high bit error rates. The authors of [36] performed a thorough review of Quality of Service (QoS) and architectures in healthcare systems. Specifically, their paper presented the features of e-health applications along with QoS for the application of specific healthcare services in telemedicine and telemedicine architecture. In [37], the authors examined both QoS and Quality of Experience (QoE) in telemedicine systems. Wireless techniques in telemedicine were presented in [38], with a specific focus on the Vertical Handoff (VHO) technique in telemedicine. In the foregoing, several survey articles have been mentioned that looked at different areas involved in telemedicine. In the present article, the reader's attention is drawn towards discussion of the communications technologies used in wearable sensor devices for vital sign monitoring in telemedicine applications. Table 1 presents an overview of previous survey articles and their respective areas of focus listed in chronological order based on the year of publication. From this table, it can be seen that early works in telemedicine focused on implementation-related issues and technologies, while recent works have focused more on policies related to standardization, QoS, and QoE. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Ref** & **Year** & **Main Focus** & **Specific Details** \\ \hline
[17] & 2000 & Internet in Telemedicine &