## 2 Healthcare Projects Using Wireless Medical Sensor Networks
Any real-time data queries about physiological or environmental data are originated by the user that contains the source address, ID, and sensor type. For a single-shot query, the sensors sample the requested data and respond a single report to the query originator, and hence complete the query. In addition, authors have developed a circadian activity rhythms program to aid context-aware power management and privacy policies. Figure 4: ALARM-NET architecture. Further Alarm-Net facilitates network and data security for physiological, environmental, behavioral parameters about the residents. Only authenticated users can access the Alarm-Net and can query the sensor networks. The IP-network is secured by secure remote password (SRP) protocol for user authentication. The wireless sensor networks are enabled with Link-layer security suites. Sensors (_i.e._, MicaZ [50] and Telos [51]) use built-in cryptosystems, _i.e._, an advanced encryption system (AES) for cryptographic operations. AES security modes supported are: none, CBC-MAC authentication-only, CTR mode encryption-only, and CMM combines with authentication and encryption [13]. The major drawback of the built-in cryptosystem is that it does not offer AES-based decryption, by which means the encrypted data cannot be accessed by an intermediary node during communication, if needed. Further, hardware based built-in cryptosystem makes the application highly platform dependent. More notably, [PERSON] _et al._ have pointed out some confidentiality infringement scenarios on Alarm-NET, such as the fact it is susceptible to adversarial confidentiality attacks, which can leak resident's location; refer to [52] for details. UbiMon (Ubiquitous monitoring environment for wearable and implantable sensors) [14] is a BSN (Body Sensor Network) architecture composed of wearable and implantable sensors using an _ad hoc_ network. The aim of the project is to provide continuous monitoring of an individual's physiological states and capture transient as well as life threatening abnormalities that can be detected and predicted. As shown in the Figure 5, the UbiMon architecture consists of the following: (i) _BSN node_: Each node is integrated with bio-sensors (ECG, SpO2, temperature). (ii) _LPU (Local Processing Unit)_: LPUs can be portable devices (PDAs, laptop, _etc._) used to the gather data from BSNs, and are known as the base station. They detect the patient's abnormalities and provide immediate warning to the physician. Apart from this function, the LPU works as a router between BSN nodes and the central server using wireless communication (for short range Bluetooth/Wi-Fi and long-range mobile  
Figure 5: UbiMon system architecture. networks such as 3G/GPRS). (iii) _CS (Central Sever)_: A CS feeds the patient data to the PD (Patient Database), and can analyze the patient's data on the basis of patient's condition, and detect potential life-threatening abnormalities. (iv) _WS (Work-station)_: The WS is the patient's data monitoring terminal (PC/laptop), which is used by the physician. Although [PERSON] _et al._ proposed and demonstrated the ubiquitous healthcare monitoring architecture, it is widely accepted that without considering security for such applications they are often vulnerable to security attacks. So the authors did not consider security for wireless healthcare monitoring, which is a paramount requirement of healthcare applications, according to government laws [39]. In 2006, [PERSON] designed a mobile healthcare project called MobiCare [16]. MobiCare provides a wide-area mobile patient monitoring system that facilitates continuous and timely monitoring of patients physiological status. It (MobiCare) potentially improves the quality-of-patient care and saving many lives. As shown in the Figure 6, the proposed system comprises of body sensor network (BSN) having wearable sensors (e.g., ECG, SpO2, and blood oxygen); a BSN manager called \"MobiCare client that is an IBM wristwatch\"; and a back-end infrastructure (_i.e._, MobiCare server).