Zigbee: Overview and Analysis

Zigbee: Overview and Analysis Zigbee is a Ad-hoc networking technology for LR-WPAN,based on IEEE 802.15.4 standard that defines the PHY and Mac Layers for Zigbee. Intended for 2.45 Ghz , 868 MHz and 915 MHz Band. Low in cost, complexity power consumption as compared to competing technologies. Intended to network inexpensive Devices. Data rates touch 250Kbps for 2.45Ghz ,40 Kbps 915Mhz and 20Kbps for 868Mhz band. Origin Of Name ZigBee The domestic honeybee, a colonial insect, lives in a hive that contains a queen, a few male drones, and thousands of worker bees. The survival, success, and future of the colony is dependent upon continuous communication of vital information between every member of the colony. The technique that honey bees use to communicate new-found food sources to other members of the colony is referred to as the ZigBee Principle. Using this silent, but powerful communication system, whereby the bee dances in a zig-zag pattern, she is able to share information such as the location, distance, and direction of a newly discovered food source to her fellow colony members. Instinctively implementing the ZigBee Principle, bees around the world industriously sustain productive hives and foster future generations of colony members. Zigbee Architecture There are three areas of architectural responsibility in Zigbee engineering effort. They are The physical and MAC layers take full advantage of the physical radio specified by IEEE 802.15.4. The 802.15.4 specification describes a peer-to-peer radio using Direct Sequence Spread Spectrum. The specification also calls out the data rates, channelization, and modulation techniques to be employed. The Zigbee Alliance specifies the logical network, security, and application software, which are implemented in a firmware stack. It is the Zigbee stack that creates the mesh networking capability. Each microcontroller/RF chip combination requires its own Zigbee stack due to the differences in microcontrollers and RF chips. Typically, the Zigbee stack is included with either the microcontroller or RF chip. The stack may belong to the chip vendor, be provided by the chip vendor from a third party source, or be provided by a third party source for a specific microcontroller/RF chip combination. The application layer is defined by profiles, of which there are two types: public profiles are those certified by the Zigbee Alliance for interoperability purposes, and private profiles are for use in closed systems. A word about the Zigbee Alliance: The following discussion includes options that require access to intellectual property available only to members of the Zigbee Alliance. There are three types of membership; all companies that plan to release products incorporating Zigbee technology must become at least adopting members, an entry-level membership that provides such benefits as access to specifications and developer conferences/workshops. ZigBee/IEEE 802.15.4 General Characteristics: Dual PHY (2.4GHz and 868/915 MHz) Data rates of 250 kbps (@2.4 GHz), 40 kbps (@ 915 MHz), and 20 kbps (@868 MHz) Optimized for low duty-cycle applications ( CSMA-CA channel access Yields high throughput and low latency for low duty cycle devices like sensors and controls Low power (battery life multi-month to years) Multiple topologies: star, peer-to-peer, mesh Addressing space of up to: 18,450,000,000,000,000,000 devices (64 bit IEEEaddress)- 65,535 networks Optional guaranteed time slot for applications requiring low latency Fully hand-shaked protocol for transfer reliability Range: 50m typical (5-500m based on environment) Use Case Scenario: It is 4:00 a.m. on a farm in Iowa. Sensors distributed throughout the fields report the moisture content in the soil and humidity of the air. The staff on the farm uses this data to decide where and when to water for optimum effect. The information also serves as an early warning system for environmental issues such as frost. Precious resources are used more efficiently and productivity increases. The sensors distributed in the field are interconnected in a mesh network. If a sensor node goes down, the network is self-healing; the nodes are able to connect with one another dynamically, finding another route to stay connected within the network. Network Topologies: It support three types of topologies. They are: 1) Star topology 2) Mesh topology 3) Cluster tree topology Star Topology: In the star topology, the communication is established between devices and a single central controller, called the PAN coordinator. The PAN coordinator may be mains powered while the devices will most likely be battery powered. Applications that benefit from this topology include home automation, personal computer (PC) peripherals, toys and games. After an FFD is activated for the first time, it may establish its own network and become the PAN coordinator. Each start network chooses a PAN identifier, which is not currently used by any other network within the radio sphere of influence. This allows each star network to operate independently. Mesh Network: A key component of the ZigBee protocol is the ability to support mesh networks. In a mesh network, nodes are interconnected with other nodes so that at least two pathways connect each node. Connections between nodes are dynamically updated. In some cases, a partial mesh network is established with some of the nodes only connected to one other node. Mesh networks are decentralized in nature; each node is self-routing and able to connect to other nodes as needed. The characteristics of mesh topology and ad-hoc routing provide greater stability in changing conditions or failure at single nodes Cluster-tree Topology: Cluster-tree network is a special case of a peer-to-peer network in which most devices are FFDs and an RFD may connect to a cluster-tree network as a leave node at the end of a branch. Any of the FFD can act as a coordinator and provide synchronization services to other devices and coordinators. Only one of these coordinators however is the PAN coordinator. The PAN coordinator forms the first cluster by establishing itself as the cluster head CLH) with a cluster identifier (CID) of zero, choosing an unused PAN identifier, and broadcasting beacon frames to neighboring devices. A candidate device receiving a beacon frame may request to join the network at the CLH. If the PAN coordinator permits the device to join, it will add this new device as a child device in its neighbor list. The advantage of this clustered structure is the increased coverage area at the cost of increased message latency. SUCCESS FACTORS: Zigbee is a low cost wireless technology, data type support, ease of installation, reliable data transfer, short range operation and is has reasonable battery life. Zigbee operates on unlicensed band and in unrestricted geographical use global implementation. IEEE 802.15.4 protocol features: Master/slave topology Automatic network configuration Dynamic slave device addressing Virtual peer-to-peer links (pairing) Full handshaking for packet transfers Power management features Up to 254 (+ master) network nodes CSMA-CA channel access mechanism 15ms frame structure TDMA slots can be allocated 28kbps 250kbps data throughput Service discovery Low impact internet capability ZigBee Applications: Zigbee networks handle multiple traffic types with their own unique characteristics, including periodic data, intermittent data, and repetitive low latency data. The characteristics of each are as follows: à ¢Ã¢â€š ¬Ã‚ ¢ Periodic data application defined rate (e.g. wireless sensor or meter). Data is typically handled using a beaconing system whereby the sensor wakes up at a set time and checks for the beacon from the PAN coordinator, it then requests to joint the network. If the coordinator accepts it, data is passed by the sensor before it goes to sleep again. This capability provides for very low duty cycles. à ¢Ã¢â€š ¬Ã‚ ¢ Intermittent data either application or external stimulus defined rate (e.g. Wireless light switch). Data can be handled in a beaconless system or disconnected. In disconnected operation, the device will only attach to the network when communications is required thus saving considerable energy. à ¢Ã¢â€š ¬Ã‚ ¢ Repetitive low latency data Allocations of time slots. (e.g. medical alerts and security systems). These applications may use the guaranteed time slot (GTS) capability when timeliness and critical data passage is required. GTS is a method of QoS that allows each device a specific duration of time as defined by the PAN coordinator in the Superframe to do whatever it requires without contention or latency. ZigBee networks are primarily intended for low duty cycle sensor networks ( procedures occur much faster than with a Bluetooth technology. Some examples where short-range, low-data, cheap wireless networks can be used are: Automatic Meter Reading provides the usage statistics for Power Management and Energy Conservation whether it is electric, natural gas, water or other utilities. Controlling the environment in HVAC systems. Lighting, temperature and other building controls help save utility usage and maintenance costs. Wireless monitoring and control systems remove expensive installation costs where wiring is difficult, extensive or part of a retrofit design. ZigBee network can help in collecting the information necessary for an effective Inventory and Logistics Management. In fleet management, vehicles can automatically transmit logged information or receive updates when inside the fleet yard. Various control and automation scenarios are possible both for homes and industries using cheap wireless communication including security systems and access control. ZigBee enables broad-based deployment of wireless networks with low-cost, low-power solutions. It provides the ability to run for years on inexpensive batteries for a host of monitoring applications: Lighting controls, AMR (Automatic Meter Reading), smoke and CO detectors, wireless telemetry, HVAC control, heating control, home security, Environmental controls, drapery and shade controls, etc. OUR IMPLEMENTATION- WIRELESS KEYBOARD Block Diagram Our implementation is divided into two sections: Transmitter and Receiver. Transmitter section: Transmitter Section consists of following: 1. Keyboard as input device 2. PS2 connector 3. Uniboard 4. Xbee Keyboard is connected to Uniboard through PS2 Connector.When a key is pressed the data is transmitted to UART0 at every falling edge of the clock pulse. PS2 Connectors data line is given to a port pin of ATMEGA128 and clock pin to the externel INT pin. Uniboard has the ATMega 128 MCU. It has two UARTs UART0,1. UART1 is directly connected to serial port via IC MAX232. Xbee is connected to the UART0 interface. MCU transmits data to UART0 and hence forwarded to Xbee. Receiver section: Receiver section comprises of following: 1. Zigbee 2. Uniboard 3. PC (gtkterm) as o/p device. Zigbee receives the data transmitted from zigbee on transmitter side using wireless communication and send it to UART0. Uniboard provides same functionality as Tx. When a frame is received at UART0, it is processed to extract the required data from the whole frame and decode data to its equivalent ASCII char . The character could be then either transmitted to UART1 via MAX232 and simultaneously display it to gtkterm or could be processed as user wants it to be. Conclusion: The ZigBee Standard enables the broad-based deployment of reliable wireless networks with low complexity, low cost solutions and provides the ability for a product to run for years on inexpensive primary batteries (for a typical monitoring application). It is also, of course, capable of inexpensively supporting robust mesh networking technologies ZigBee is all set to provide the consumers with ultimate flexibility, mobility, and ease of use by building wireless intelligence and capabilities into every day devices. The mission of the ZigBee Working Group is to bring about the existence of a broad range of interoperable consumer devices by establishing open industry specifications for unlicensed, untethered peripheral, control and entertainment devices requiring the lowest cost and lowest power consumption communications between compliant devices anywhere in and around the home. Issues in Contemporary Nursing: Values and Ethics Issues in Contemporary Nursing: Values and Ethics Paul Monahan Nursing is a career that has spanned centuries with many of its foundations following rise of Christianity. Since then, there have been many different views and opinions of what nursing is and what it should and should not be by many different theorists and organisations. In this essay, I will explore this in a number of different ways, the first of which will be by discussing the definitions and core values of nursing, where I hope to outline some of the definitions from both theorists, and organisations such as the Nursing Midwifery Council (NMC) who outline the duties and responsibilities of registered nurses to ensure the safety of patients in their care. I will also address my own views of nursing as they stand now and through the course of this essay, hope to demonstrate how they have changed based on what I have learned through research and practice experience. Needless to say, the media has a significant role to play in the public perception of the nursing profession and I h ope to contrast the opinions expressed against my own views. Secondly, I also wish to discuss the NMC’s role in ensuring that nurses act professionally and ethically by looking at the code and key guidance for safe practice. The third point I will cover will focus on the many opportunities that nurses today can take advantage of, many of which include international travel which may not necessarily been possible when working in an acute hospital unit. Finally I will discuss contemporary issue in nursing which I have decided to discuss the Care Quality Commission (CQC), and their role it plays in ensuring that there is a high standard of care for all patients in all areas of healthcare. My goal for this essay is to expand on what I already know about nursing and learn more about the profession through experience and research. There have been many different theories surrounding the profession of nursing, as a result of these theories; there have been many different definitions formed by theorists and organisations alike. The Royal College of Nursing (RCN) has developed a definition which is built as a core with six defining characteristics. They defined nursing as â€Å"The use of clinical judgement in the provision of care to enable people to improve, maintain, or recover health, to cope with health problems, and to achieve the best possible quality of life, whatever their disease or disability, until death.† (RCN, ‘Defining Nursing’ 2003). The characteristics which follow this statement suggest that nurses should have a purpose, mode of intervention, a domain of practice, a focus towards the patient as a person, a value base which respects the dignity, autonomy and individuality of all persons, whether they are patients, relatives or colleagues and finally a commitment to working alon gside others, rather than as an individual. In reality, everybody has their own view of what nursing is and I feel that I am no exception. Before I started studying nursing, my previous experiences were shaped by the views of those around me, many of whom believed that being intelligent wasn’t necessarily important as being caring. I then started working as a healthcare assistant and found that there was so much more to nursing than just caring for patients, a nurse needed to have a vast amount of medical knowledge as well as being able to communicate well with other health professionals. However the media has had a significant role to play in shaping the public perception of nursing in today’s society. Tabloid newspapers in particular have done their part to change the public perception of nursing, often by focusing on isolated incidents of poor practice and through glamorising or sensationalising the facts with the journalist’s or editors own opinions in order to increase its commercial value whilst simultaneously lowering its factual merit in order to attempt to damage the reputation of the nursing profession and through that the reputations of many hard-working individuals that take pride in their work. In 2012, the National Health Service England (NHS England) published an informational leaflet entitled â€Å"Our Culture of Compassionate Care†. It outlined the 6 C’s. These 6 C’s are; Care: Which defines the work of healthcare services as patients expect high levels of care through every stage of their life; Compassion: this is by far one of the most important aspects of patient care. Treating patients with respect and dignity is an important part of their healthcare as they need to feel valued in order to recover quickly; Competence: This aspect means that everybody involved with a patients care should have the abilities in order to do their role and to care for the patient with their safety and health in mind; Co mmunication: Communication is central to the therapeutic relationship between carer and patient, there has a been a number of different definitions of patient-centred communication. A definition that I found to be most fitting for patient-centred communication is one used by Langwitz et al., in 1998. â€Å"Patient-centred communication is defined as communication that invites and encourages the patient to participate and negotiate in decision-making regarding their own care† (Langwitz et al., 1998, p.230); Courage: All healthcare professionals have to be able to do what is right for the patients that they care for, and to speak up when they have concerns about colleagues practice or competence; Commitment; A commitment to patients is the cornerstone of the NHS, in order to improve the quality of care, all healthcare workers should be committed to providing the best care that they are able to provide to their patients. Main Point 2 – Professional Ethical Nursing Ethics is a topic that carries a vast amount of study and debate. It can also become a framework within which we live our day to day lives. There has also been a lot of study in the area of professional ethics for nurses with many organisations and regulators such as the NMC publishing ethical standards for all nurses to follow. These ethical standards influence areas such as training and development for nurses and student nurses, best practice for patient care and ensuring that patients receive high quality care from all service providers. The NMC is the regulator for nurses and midwives in England, Wales, Northern Ireland and Scotland. Their role is to protect the wellbeing and health of the public, set the standards or training, education, training, conduct and performance so that nurses and midwives can deliver a high level of care throughout their careers. They also have processes in place to investigate cases of misconduct against nurses and midwives who fall short of their standards (Nursing Midwifery Council 2011). The code has 17 categories split across 4 chapters. These focus on areas such as maintaining patient trust, person focused care, promoting good health, providing a high standard of care and to be open and honest as to uphold the reputation of your profession. In order to be ethical and professional at all times, nurses learn and follow the code in all areas of practice. Safeguarding vulnerable people is another issue that nurses face in regards to acting professionally, the department of health defines a vulnerable adult as a person â€Å"Who is or may be in need of community care services by reason of mental or other disability, age or illness; and who is or may be unable to take care of him or herself, or unable to protect him or herself against significant harm or exploitation† (No Secrets: Guidance on Developing and implementing multi-agency policies and procedures to protect vulnerable adults from abuse. 2000). It is important that nurses are appropriately trained to spot signs of abuse and that they are aware of the procedures set out by their trust for reporting concerns about patient safety in an appropriate manner. The Safeguarding Adults Boards of Brighton and Hove, East Sussex and West Sussex outlined a policy in June 2007 which was updated in 2013 for anybody working in a health or social care setting. It lays out the seven differ ent categories of abuse and the signs of each, as well as stressing that a person may not experience only one type of abuse and that there can be cross overs between the categories based on an individual incident. It also outlines what staff can do if they receive a disclosure of abuse from a service user. Main Point 3 – Values Personhood Main Point 4 – Contemporary Issues in Nursing The Care Quality Commission make sure that all hospitals, care homes, dental and general practices and other care services in England provide the people who use them with safe, effective and high-quality care and encourage these services to make improvements in care (Care Quality Commission, 2014). They do this by setting standards that all people have a right to expect when they are in receipt of care; they also inspect and regulate care services and register care services that are able to meet these standards whilst outlining improvements that need to be made in cases of an institution not meeting quality and safety standards; they are able to investigate claims made against care services made by care users or members of the public and take appropriate action if these claims are based on truth; they also assess and rate the quality of care services which gives members of the public a choice in choosing high quality care based on their needs. The also publish a report to Parliament on an annual basis outlining how resources in the healthcare sector are being used in order to allow Parliament to make decisions of future expenditure in healthcare. There are five national standards that all care services must meet in order to be registered with the CQC. These standards are vital to the provision of high quality care so they are central areas that are covered when the CQC performs an inspection. These standards are as follows: You should expect to be respected, involved in your care and support, and told what’s happening at every stage. This means that a patient should always be kept informed of any changes in their care plan and that the opinions and views of the patient should be considered and respected when making medical decisions; You should expect care, treatment and support that meets your needs. This means that care workers should fill out appropriate risk assessments and ensure that patients dietary preferences are clearly noted in order to create a care plan that is appropriate for the patient; You should expect to be safe. This means that all staff must respect their patients beliefs and rights, it also means that the patient should be cared for in areas that are clean and that they will receive their prescribed medication when they need it, staff should also make sure equipment used on patients, such as hoists, are well maintained and safe for use on patients; You should expect to be cared for by staff with the right skills to do their jobs properly which means that any care staff that a patient requires are sufficiently trained in their role and that students under their instruction are sufficiently supervised during patient contact. And you should expect your care provider to routinely check the quality of their services; this ensures that patient care is of high quality and that all other standards are maintained by a care service. The CQC also performs unannounced inspections of care services in order to ensure that patients are receiving the highest level of care at all times. By registering these services, the CQC assures the public that they will receive the best possible care; they also provide copies of their inspection reports online for members of the public to read in order to inform them of the quality of care provided by a service that they may be going to use. Conclusion In conclusion, I have learnt about some of the definitions and core values of the nursing profession, I have also looked at the Nursing and Midwifery Council and their role in ensuring that all nurses work professionally and within their scope of practice. I have also explored my own views of nursing and how these views contrast to the public perception of nursing that is displayed in the media. I looked at the NMC’s code for nurses and midwives and the importance of recognising safeguarding concerns and how policy and legislation can guide nurses to report safeguarding concerns in an appropriate manner. References / Bibliography Clark, J., Denton, S., Burns, J., Rawstorne, D., Warrington, E., Kitson, A., Beacock, C., Kenison, L., Scott, C., Belgrave, J. and Salmon, A. (2003).Defining Nursing. 1st ed. [ebook] London: Royal College of Nursing. Available at: http://www.rcn.org.uk/__data/assets/pdf_file/0008/78569/001998.pdf [Accessed 25 Apr. 2014]. Cqc.org.uk, (2014).Care Quality Commission | Homepage. [online] Available at: http://www.cqc.org.uk/ [Accessed 26 Apr. 2014]. Langwitz, W., Eich, P., Kiss, A. and Wossmer, B. (1998). Improving Communication Skills-A Randomized Controlled Behaviorally Oriented Intervention Study for Residents in Internal Medicine.Psychosomatic Medicine: Journal of Biobehavioral Medicine, [online] 60(3), pp.268-276. Available at: http://journals.lww.com/psychosomaticmedicine/Fulltext/1998/05000/Improving_Communication_Skills_A_Randomized.9.aspx [Accessed 25 Apr. 2014]. McCabe, C., Timmins, F. and Campling, J. (2006).Communication skills for nursing practice. 1st ed. Basingstoke [England]: Palgrave Macmillan. National Health Service England, (2012).Our Culture of Compassionate Care. NHS England. No Secrets: Guidance on developing and implementing multi-agency policies and procedures to protect vulnerable adults from abuse. (2000). 1st ed. [ebook] London: Department of Health, pp.9-10. Available at: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/194272/No_secrets__guidance_on_developing_and_implementing_multi-agency_policies_and_procedures_to_protect_vulnerable_adults_from_abuse.pdf [Accessed 26 Apr. 2014]. Sussex Multi-Agency Policy and Procedures for Safeguarding Adults at Risk. (2007). 2nd ed. [ebook] Brighton Hove Safeguarding Adults Board, East Sussex Safeguarding Adults at Risk, West Sussex Adults Safeguarding Board. Available at: http://pansussexadultssafeguarding.proceduresonline.com/pdf/pdf_copy/Full copy Sussex Multi Agency Policy and Procedures.pdf [Accessed 26 Apr. 2014]. The NMC Code of Professional Conduct: Standards for conduct, performance and ethics. (2004). 2nd ed. London: Nursing Midwifery Council. Torjesen, I. (2008). Acting for Vulnerable Adults.The Nursing Tumes. [online] Available at: http://www.nursingtimes.net/acting-for-vulnerable-adults/1732771.article [Accessed 26 Apr. 2014]. Wheldon, J. (2005). Nurses too busy to care for dying patients.Daily Mail. [online] Available at: http://www.dailymail.co.uk/health/article-356403/Nurses-busy-care-dying-patients.html [Accessed 25 Apr. 2014]. Bibliography 1