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78-495: Zigbee is an IEEE 802.15.4 -based specification for a suite of high-level communication protocols used to create personal area networks with small, low-power digital radios , such as for home automation , medical device data collection, and other low-power low-bandwidth needs, designed for small scale projects which need wireless connection. Hence, Zigbee is a low-power, low-data-rate, and close proximity (i.e., personal area) wireless ad hoc network . The technology defined by

156-476: A mesh network of intermediate devices to reach more distant ones. Zigbee is typically used in low data rate applications that require long battery life and secure networking. (Zigbee networks are secured by 128-bit symmetric encryption keys.) Zigbee has a defined rate of up to 250  kbit/s , best suited for intermittent data transmissions from a sensor or input device. Zigbee was conceived in 1998, standardized in 2003, and revised in 2006. The name refers to

234-502: A random exponential backoff algorithm; acknowledgments do not adhere to this discipline. Common data transmission utilizes unallocated slots when beaconing is in use; again, confirmations do not follow the same process. Confirmation messages may be optional under certain circumstances, in which case a success assumption is made. Whatever the case, if a device is unable to process a frame at a given time, it simply does not confirm its reception: timeout-based retransmission can be performed

312-697: A Zigbee router, if not the Zigbee coordinator; the switch node is typically a Zigbee end device. In beacon-enabled networks, Zigbee routers transmit periodic beacons to confirm their presence to other network nodes. Nodes may sleep between beacons, thus extending their battery life. Beacon intervals depend on data rate; they may range from 15.36 milliseconds to 251.65824 seconds at 250 kbit/s, from 24 milliseconds to 393.216 seconds at 40 kbit/s and from 48 milliseconds to 786.432 seconds at 20 kbit/s. Long beacon intervals require precise timing, which can be expensive to implement in low-cost products. In general,

390-606: A battery life of at least two years to pass certification. Typical application areas include: Zigbee is not for situations with high mobility among nodes. Hence, it is not suitable for tactical ad hoc radio networks in the battlefield, where high data rate and high mobility is present and needed. The first Zigbee application profile, Home Automation, was announced November 2, 2007. Additional application profiles have since been published. The Zigbee Smart Energy 2.0 specifications define an Internet Protocol -based communication protocol to monitor, control, inform, and automate

468-465: A database of information on related personal area networks. Thus, the PHY manages the physical radio transceiver , performs channel selection along with energy and signal management functions. It operates on one of three possible unlicensed frequency bands: The original 2003 version of the standard specifies two physical layers based on direct-sequence spread spectrum (DSSS) techniques: one working in

546-416: A heterogeneous network is a wireless light switch : The Zigbee node at the lamp may constantly receive since it is reliably powered by the mains supply to the lamp, while a battery-powered light switch would remain asleep until the switch is thrown. In this case, the switch wakes up, sends a command to the lamp, receives an acknowledgment, and returns to sleep. In such a network the lamp node will be at least

624-450: A link, acquired through pre-installation, agreement or transport. Establishment of link keys is based on a master key which controls link key correspondence. Ultimately, at least, the initial master key must be obtained through a secure medium (transport or pre-installation), as the security of the whole network depends on it. Link and master keys are only visible to the application layer. Different services use different one-way variations of

702-437: A neighboring device belongs to the network and discovers new neighbors and routers. The routing protocol used by the network layer is AODV . To find a destination device, AODV is used to broadcast a route request to all of its neighbors. The neighbors then broadcast the request to their neighbors and onward until the destination is reached. Once the destination is reached, a route reply is sent via unicast transmission following

780-441: A network and the services that they offer, which endpoints can report when queried by the discovering device (which has previously obtained their addresses). Matching services can also be used. The use of cluster identifiers enforces the binding of complementary entities using the binding tables, which are maintained by Zigbee coordinators, as the table must always be available within a network and coordinators are most likely to have

858-465: A network key provided by the trust center (through the initially insecure channel) to communicate. IEEE 802.15.4 IEEE standard 802.15.4 is intended to offer the fundamental lower network layers of a type of wireless personal area network (WPAN), which focuses on low-cost, low-speed ubiquitous communication between devices. It can be contrasted with other approaches, such as Wi-Fi , which offers more bandwidth and requires more power. The emphasis

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936-410: A network, allocate addresses, and add and remove devices. This layer makes use of star, mesh and tree topologies. The data entity of the transport layer creates and manages protocol data units at the direction of the application layer and performs routing according to the current topology. The control entity handles the configuration of new devices and establishes new networks. It can determine whether

1014-407: A network, and discovering and securing devices. The Zigbee network layer natively supports both star and tree networks, and generic mesh networking . Every network must have one coordinator device. Within star networks, the coordinator must be the central node. Both trees and meshes allow the use of Zigbee routers to extend communication at the network level. Another defining feature of Zigbee

1092-490: A node briefly checks to see that other nodes are not talking before it starts. CSMA/CA is not used in three notable exceptions: The main functions of the network layer are to ensure correct use of the MAC sublayer and provide a suitable interface for use by the next upper layer, namely the application layer. The network layer deals with network functions such as connecting, disconnecting, and setting up networks. It can establish

1170-508: A number of times, following after that a decision of whether to abort or keep trying. Because the predicted environment of these devices demands maximization of battery life, the protocols tend to favor the methods which lead to it, implementing periodic checks for pending messages, the frequency of which depends on application needs. Regarding secure communications, the MAC sublayer offers facilities which can be harnessed by upper layers to achieve

1248-684: A per product and annual fee. Adopter members are allowed access to completed CSA specifications and standards, like Zigbee. They also gain access to Alliance technology logos and trademarks for certified products Participant members have voting rights in Alliance Working Group teams and play a role in Zigbee or Matter development alongside access to Alliance technical working groups, and have early access to specifications and standards for product development. Promoter members enjoy all other member level benefits as well as help lead with final approval on all standards developed by

1326-534: A permanent power supply. Backups, managed by higher-level layers, may be needed by some applications. Binding requires an established communication link; after it exists, whether to add a new node to the network is decided, according to the application and security policies. Communication can happen right after the association. Direct addressing uses both radio address and endpoint identifier, whereas indirect addressing uses every relevant field (address, endpoint, cluster, and attribute) and requires that they are sent to

1404-399: A reasonable tradeoff between simplicity and robustness. Additionally, a superframe structure, defined by the coordinator, may be used, in which case two beacons act as its limits and provide synchronization to other devices as well as configuration information. A superframe consists of sixteen equal-length slots, which can be further divided into an active part and an inactive part, during which

1482-410: Is also part of the application layer. A network node consists of an IEEE 802.15.4-conformant radio transceiver and one or more device descriptions (collections of attributes that can be polled or set or can be monitored through events). The transceiver is the basis for addressing, and devices within a node are specified by an endpoint identifier in the range 1 to 240. For applications to communicate,

1560-505: Is also supported, where the coordinator of the network will necessarily be the central node. Such a network can originate when an FFD decides to create its own PAN and declare itself its coordinator, after choosing a unique PAN identifier. After that, other devices can join the network, which is fully independent from all other star networks. Frames are the basic unit of data transport, of which there are four fundamental types (data, acknowledgment, beacon and MAC command frames), which provide

1638-521: Is another, insecure MAC mode, which allows access control lists merely as a means to decide on the acceptance of frames according to their (presumed) source. Connectivity Standards Alliance The Connectivity Standards Alliance ( CSA ), formerly the Zigbee Alliance , is a group of companies that maintain and publish the Zigbee and Matter standard, along with several others. Over

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1716-479: Is being developed by partners including: Zigbee Smart Energy relies on Zigbee IP, a network layer that routes standard IPv6 traffic over IEEE 802.15.4 using 6LoWPAN header compression. In 2009, the Radio Frequency for Consumer Electronics Consortium (RF4CE) and Connectivity Standards Alliance (formerly Zigbee Alliance) agreed to deliver jointly a standard for radio frequency remote controls. Zigbee RF4CE

1794-621: Is designed for a broad range of consumer electronics products, such as TVs and set-top boxes. It promised many advantages over existing remote control solutions, including richer communication and increased reliability, enhanced features and flexibility, interoperability, and no line-of-sight barrier. The Zigbee RF4CE specification uses a subset of Zigbee functionality allowing to run on smaller memory configurations in lower-cost devices, such as remote control of consumer electronics. The radio design used by Zigbee has few analog stages and uses digital circuits wherever possible. Products that integrate

1872-589: Is facilities for carrying out secure communications, protecting the establishment and transport of cryptographic keys, ciphering frames, and controlling devices. It builds on the basic security framework defined in IEEE 802.15.4. Zigbee-style self-organizing ad hoc digital radio networks were conceived in the 1990s. The IEEE 802.15.4-2003 Zigbee specification was ratified on December 14, 2004. The Connectivity Standards Alliance (formerly Zigbee Alliance) announced availability of Specification 1.0 on June 13, 2005, known as

1950-635: Is formed by members with a focus on promoting Alliance technologies in the China market. The Europe Interest Group (EIG) consisting of 98+ member companies and 216 individual members has a focus on the European market . The name Zigbee is a registered trademark of this group, and is not a single technical standard. The organization publishes application profiles that allow multiple original equipment manufacturer (OEM) vendors to create interoperable products. The relationship between IEEE 802.15.4 and Zigbee

2028-540: Is generally 0–20  dBm (1–100 mW). There are three classes of Zigbee devices: The current Zigbee protocols support beacon-enabled and non-beacon-enabled networks. In non-beacon-enabled networks, an unslotted CSMA/CA channel access mechanism is used. In this type of network, Zigbee routers typically have their receivers continuously active, requiring additional power. However, this allows for heterogeneous networks in which some devices receive continuously while others transmit when necessary. The typical example of

2106-421: Is managed by the digital stream into the modulator. Binary phase-shift keying (BPSK) is used in the 868 and 915 MHz bands, and offset quadrature phase-shift keying (OQPSK) that transmits two bits per symbol is used in the 2.4 GHz band. The raw, over-the-air data rate is 250  kbit/s per channel in the 2.4 GHz band, 40 kbit/s per channel in the 915 MHz band, and 20 kbit/s in

2184-443: Is on very low-cost communication of nearby devices with little to no underlying infrastructure, intending to exploit this to lower power consumption even more. The basic framework conceives a 10-meter communications range with line of sight at a transfer rate of 250 kbit/s. Bandwidth tradeoffs are possible to favor more radically embedded devices with even lower power requirements for increased battery operating time, through

2262-408: Is only limited by the distance between each pair of nodes. They are meant to serve as the basis for ad hoc networks capable of performing self-management and organization. Since the standard does not define a network layer, routing is not directly supported, but such an additional layer can add support for multihop communications. Further topological restrictions may be added; the standard mentions

2340-520: Is optional. Data transfers from the coordinator usually follow device requests: if beacons are in use, these are used to signal requests; the coordinator acknowledges the request and then sends the data in packets which are acknowledged by the device. The same is done when superframes are not in use, only in this case there are no beacons to keep track of pending messages. Point-to-point networks may either use unslotted CSMA/CA or synchronization mechanisms; in this case, communication between any two devices

2418-414: Is possible, whereas in "structured" modes one of the devices must be the network coordinator. In general, all implemented procedures follow a typical request-confirm/indication-response classification. The physical medium is accessed through a CSMA/CA access method. Networks which are not using beaconing mechanisms utilize an unslotted variation which is based on the listening of the medium, leveraged by

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2496-512: Is possible. Beyond these three bands, the IEEE 802.15.4c study group considered the newly opened 314–316 MHz, 430–434 MHz, and 779–787 MHz bands in China, while the IEEE 802.15 Task Group 4d defined an amendment to 802.15.4-2006 to support the new 950–956 MHz band in Japan. The first standard amendments by these groups were released in April 2009. In August 2007 , IEEE 802.15.4a

2574-402: Is responsible for defining the role of a device as either coordinator or end device, as mentioned above, but also for the discovery of new devices on the network and the identification of their offered services. It may then go on to establish secure links with external devices and reply to binding requests accordingly. The application support sublayer (APS) is the other main standard component of

2652-762: Is similar to that between IEEE 802.11 and the Wi-Fi Alliance . The requirements for membership in the Alliance cause problems for free-software developers working with Zigbee because the annual fee conflicts with the GNU General Public Licence . The requirements for developers to join the CSA also conflict with most other free-software licenses. The CSA board of directors has been asked to make their license compatible with GPL, but refused. Bluetooth has GPL-licensed implementations. However,

2730-404: Is the transmission of the network key, which confers a unified security layer to the grid, to a new connecting device. The Zigbee security architecture is based on CCM*, which adds encryption- and integrity-only features to CCM mode . Zigbee uses 128-bit keys to implement its security mechanisms. A key can be associated either to a network, being usable by Zigbee layers and the MAC sublayer, or to

2808-697: The 2.4  GHz band being primarily used for lighting and home automation devices in most jurisdictions worldwide. While devices for commercial utility metering and medical device data collection often use sub-GHz frequencies, (902-928  MHz in North America, Australia, and Israel, 868-870 MHz in Europe, 779-787 MHz in China, even those regions and countries still using the 2.4 GHz for most globally sold Zigbee devices meant for home use. With data rates varying from around 20 kbit/s for sub-GHz bands to around 250 kbit/s for channels on

2886-561: The ZigBee 2004 Specification . In September 2006, the Zigbee 2006 Specification was announced, obsoleting the 2004 stack The 2006 specification replaces the message and key–value pair structure used in the 2004 stack with a cluster library . The library is a set of standardised commands, attributes and global artifacts organised under groups known as clusters with names such as Smart Energy, Home Automation, and Zigbee Light Link . In January 2017, Connectivity Standards Alliance renamed

2964-418: The waggle dance of honey bees after their return to the beehive. Zigbee is a low-power wireless mesh network standard targeted at battery-powered devices in wireless control and monitoring applications. Zigbee delivers low-latency communication. Zigbee chips are typically integrated with radios and with microcontrollers . Zigbee operates in the industrial, scientific and medical ( ISM ) radio bands. With

3042-519: The 2.4 GHz band range). Zigbee builds on the physical layer and media access control defined in IEEE standard 802.15.4 for low-rate wireless personal area networks (WPANs). The specification includes four additional key components: network layer , application layer , Zigbee Device Objects (ZDOs) and manufacturer-defined application objects. ZDOs are responsible for some tasks, including keeping track of device roles, managing requests to join

3120-404: The 868 MHz band. The actual data throughput will be less than the maximum specified bit rate because of the packet overhead and processing delays. For indoor applications at 2.4 GHz transmission distance is 10–20 m, depending on the construction materials, the number of walls to be penetrated and the output power permitted in that geographical location. The output power of the radios

3198-402: The 868/915 MHz bands with transfer rates of 20 and 40 kbit/s, and one in the 2450 MHz band with a rate of 250 kbit/s. The 2006 revision improves the maximum data rates of the 868/915 MHz bands, bringing them up to support 100 and 250 kbit/s as well. Moreover, it goes on to define four physical layers depending on the modulation method used. Three of them preserve

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3276-558: The Alliance by holding a seat on the Alliance Board of Directors. They pay an unknown one-time initiation fee as well as an annual membership fee of $ 105,000. As of 2024 there are 33 promoter members of the CSA who facilitate the promotion and advertisement of CSA developed standards, primarily Matter. The Alliance also has two regional member groups in China and Europe : The Connectivity Standards Alliance Member Group China (CMGC)

3354-471: The DSSS approach: in the 868/915 MHz bands, using either binary or, optionally, offset quadrature phase-shift keying (QPSK); in the 2450 MHz band, using QPSK. An optional alternative 868/915 MHz layer is defined using a combination of binary keying and amplitude-shift keying (thus based on parallel, not sequential, spread spectrum; PSSS). Dynamic switching between supported 868/915 MHz PHYs

3432-588: The IEEE 802.15 standard does not use 802.1D or 802.1Q; i.e., it does not exchange standard Ethernet frames . The physical frame-format is specified in IEEE802.15.4-2011 in section 5.2. It is tailored to the fact that most IEEE 802.15.4 PHYs only support frames of up to 127 bytes (adaptation layer protocols such as the IETF's 6LoWPAN provide fragmentation schemes to support larger network layer packets). No higher-level layers or interoperability sublayers are defined in

3510-411: The IEEE 802.15.4-2003 Low-rate Wireless Personal Area Network (LR-WPAN) standard. The standard specifies the lower protocol layers —the physical layer (PHY), and the media access control portion of the data link layer . The basic channel access mode is carrier-sense multiple access with collision avoidance (CSMA/CA). That is, the nodes communicate in a way somewhat analogous to how humans converse:

3588-595: The IEEE Standards Association Board approved IEEE 802.15.4e which concluded all Task Group 4e efforts. The medium access control (MAC) enables the transmission of MAC frames through the use of the physical channel. Besides the data service, it offers a management interface and itself manages access to the physical channel and network beaconing . It also controls frame validation, guarantees time slots and handles node associations. Finally, it offers hook points for secure services. Note that

3666-534: The MAC through a convergence sublayer. Implementations may rely on external devices or be purely embedded, self-functioning devices. The physical layer is the bottom layer in the OSI reference model used worldwide, and protocols layers transmit packets using it The physical layer (PHY) provides the data transmission service. It also, provides an interface to the physical layer management entity , which offers access to every physical layer management function and maintains

3744-409: The Zigbee protocols minimize the time the radio is on, so as to reduce power use. In beaconing networks, nodes only need to be active while a beacon is being transmitted. In non-beacon-enabled networks, power consumption is decidedly asymmetrical: Some devices are always active while others spend most of their time sleeping. Except for Smart Energy Profile 2.0, Zigbee devices are required to conform to

3822-657: The Zigbee specification is intended to be simpler and less expensive than other wireless personal area networks (WPANs), such as Bluetooth or more general wireless networking such as Wi-Fi (or Li-Fi ). Applications include wireless light switches, home energy monitors , traffic management systems, and other consumer and industrial equipment that requires short-range low-rate wireless data transfer. Its low power consumption limits transmission distances to 10–100 meters (33–328 ft) line-of-sight , depending on power output and environmental characteristics. Zigbee devices can transmit data over long distances by passing data through

3900-453: The available PHYs with several additional PHYs: one for 780 MHz band using O-QPSK or MPSK, another for 950 MHz using GFSK or BPSK . IEEE 802.15.4e was chartered to define a MAC amendment to the existing standard 802.15.4-2006 which adopts a channel hopping strategy to improve support for the industrial market. Channel hopping increases robustness against external interference and persistent multi-path fading. On February 6, 2012,

3978-474: The available information, device discovery may follow different methods. When the network address is known, the IEEE address can be requested using unicast communication. When it is not, petitions are broadcast . End devices will simply respond with the requested address while a network coordinator or a router will also send the addresses of all the devices associated with it. This extended discovery protocol permits external devices to find out about devices in

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4056-421: The cluster tree as a structure which exploits the fact that an RFD may only be associated with one FFD at a time to form a network where RFDs are exclusively leaves of a tree, and most of the nodes are FFDs. The structure can be extended as a generic mesh network whose nodes are cluster tree networks with a local coordinator for each cluster, in addition to the global coordinator. A more structured star pattern

4134-405: The coordinator may enter power saving mode, not needing to control its network. Within superframes contention occurs between their limits, and is resolved by CSMA/CA . Every transmission must end before the arrival of the second beacon. As mentioned before, applications with well-defined bandwidth needs can use up to seven domains of one or more contentionless guaranteed time slots, trailing at

4212-686: The coordinator of a personal area network just as it may function as a common node. It implements a general model of communication which allows it to talk to any other device: it may also relay messages, in which case it is dubbed a coordinator (PAN coordinator when it is in charge of the whole network). On the other hand, there are reduced-function devices (RFD). These are meant to be extremely simple devices with very modest resource and communication requirements; due to this, they can only communicate with FFDs and can never act as coordinators. Networks can be built as either peer-to-peer or star networks. However, every network needs at least one FFD to work as

4290-450: The coordinator of the network. Networks are thus formed by groups of devices separated by suitable distances. Each device has a unique 64-bit identifier, and if some conditions are met, short 16-bit identifiers can be used within a restricted environment. Namely, within each PAN domain, communications will probably use short identifiers. Peer-to-peer (or point-to-point) networks can form arbitrary patterns of connections, and their extension

4368-410: The definition of not one, but several physical layers. Lower transfer rates of 20 and 40 kbit/s were initially defined, with the 100 kbit/s rate being added in the current revision. Even lower rates can be used, which results in lower power consumption. As already mentioned, the main goal of IEEE 802.15.4 regarding WPANs is the emphasis on achieving low manufacturing and operating costs through

4446-470: The delivery and use of energy and water. It is an enhancement of the Zigbee Smart Energy version 1 specifications. It adds services for plug-in electric vehicle charging, installation, configuration and firmware download, prepay services, user information and messaging, load control, demand response and common information and application profile interfaces for wired and wireless networks. It

4524-502: The desired level of security. Higher-layer processes may specify keys to perform symmetric cryptography to protect the payload and restrict it to a group of devices or just a point-to-point link; these groups of devices can be specified in access control lists . Furthermore, MAC computes freshness checks between successive receptions to ensure that presumably old frames, or data which is no longer considered valid, does not transcend to higher layers. In addition to this secure mode, there

4602-427: The devices that support them must use a common application protocol (types of messages, formats and so on); these sets of conventions are grouped in profiles . Furthermore, binding is decided upon by matching input and output cluster identifiers unique within the context of a given profile and associated to an incoming or outgoing data flow in a device. Binding tables contain source and destination pairs. Depending on

4680-478: The end of the superframe. The first part of the superframe must be sufficient to give service to the network structure and its devices. Superframes are typically utilized within the context of low-latency devices, whose associations must be kept even if inactive for long periods of time. Data transfers to the coordinator require a beacon synchronization phase, if applicable, followed by CSMA/CA transmission (by means of slots if superframes are in use); acknowledgment

4758-477: The establishment and transport of cryptographic keys and encrypting data. It builds on the basic security framework defined in IEEE 802.15.4. The basic mechanism to ensure confidentiality is the adequate protection of all keying material. Keys are the cornerstone of the security architecture; as such their protection is of paramount importance, and keys are never supposed to be transported through an insecure channel . A momentary exception to this rule occurs during

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4836-425: The initial phase of the addition to the network of a previously unconfigured device. Trust must be assumed in the initial installation of the keys, as well as in the processing of security information. The Zigbee network model must take particular care of security considerations, as ad hoc networks may be physically accessible to external devices. Also, the state of the working environment cannot be predicted. Within

4914-409: The layers of the protocol stack . An application may consist of communicating objects which cooperate to carry out the desired tasks. Tasks will typically be largely local to each device, such as the control of each household appliance. The focus of Zigbee is to distribute work among many different devices which reside within individual Zigbee nodes which in turn form a network. The objects that form

4992-411: The library to Dotdot and announced it as a new protocol to be represented by an emoticon ( ||: ) . They also announced it will now additionally run over other network types using Internet Protocol and will interconnect with other standards such as Thread . Since its unveiling, Dotdot has functioned as the default application layer for almost all Zigbee devices. Zigbee Pro, also known as Zigbee 2007,

5070-491: The link key to avoid leaks and security risks. Key distribution is one of the most important security functions of the network. A secure network will designate one special device, the trust center , which other devices trust for the distribution of security keys. Ideally, devices will have the trust center address and initial master key preloaded; if a momentary vulnerability is allowed, it will be sent as described above. Typical applications without special security needs will use

5148-525: The lowest cost path back to the source. Once the source receives the reply, it updates its routing table with the destination address of the next hop in the path and the associated path cost. The application layer is the highest-level layer defined by the specification and is the effective interface of the Zigbee system to its end users. It comprises the majority of components added by the Zigbee specification: both ZDO (Zigbee device object) and its management procedures, together with application objects defined by

5226-404: The manufacturer, are considered part of this layer. This layer binds tables, sends messages between bound devices, manages group addresses, reassembles packets, and transports data. It is responsible for providing service to Zigbee device profiles. The ZDO (Zigbee device object), a protocol in the Zigbee protocol stack, is responsible for overall device management, security keys, and policies. It

5304-456: The network communicate using the facilities provided by APS, supervised by ZDO interfaces. Within a single device, up to 240 application objects can exist, numbered in the range 1–240. 0 is reserved for the ZDO data interface and 255 for broadcast; the 241-254 range is not currently in use but may be in the future. Two services are available for application objects to use (in Zigbee 1.0): Addressing

5382-520: The network coordinator, which maintains associations and translates requests for communication. Indirect addressing is particularly useful to keep some devices very simple and minimize their need for storage. Besides these two methods, broadcast to all endpoints in a device is available, and group addressing is used to communicate with groups of endpoints belonging to a specified set of devices. As one of its defining features, Zigbee provides facilities for carrying out secure communications , protecting

5460-522: The power consumption of other devices on a Zigbee network. Thus, radios are tested with guidance given by Clause 6 of the 802.15.4-2006 Standard. This standard specifies operation in the unlicensed 2.4 to 2.4835 GHz (worldwide), 902 to 928 MHz (Americas and Australia) and 868 to 868.6 MHz (Europe) ISM bands . Sixteen channels are allocated in the 2.4 GHz band, spaced 5 MHz apart, though using only 2 MHz of bandwidth each. The radios use direct-sequence spread spectrum coding, which

5538-477: The protocol stack, different network layers are not cryptographically separated, so access policies are needed, and conventional design assumed. The open trust model within a device allows for key sharing, which notably decreases potential cost. Nevertheless, the layer which creates a frame is responsible for its security. As malicious devices may exist, every network layer payload must be ciphered, so unauthorized traffic can be immediately cut off. The exception, again,

5616-406: The radio and microcontroller into a single module are available. The Zigbee qualification process involves a full validation of the requirements of the physical layer. All radios derived from the same validated semiconductor mask set would enjoy the same RF characteristics. Zigbee radios have very tight constraints on power and bandwidth. An uncertified physical layer that malfunctions can increase

5694-441: The stack, and as such it offers a well-defined interface and control services. It works as a bridge between the network layer and the other elements of the application layer: it keeps up-to-date binding tables in the form of a database, which can be used to find appropriate devices depending on the services that are needed and those the different devices offer. As the union between both specified layers, it also routes messages across

5772-399: The standard. Other specifications, such as Zigbee , SNAP, and 6LoWPAN / Thread , build on this standard. RIOT , OpenWSN , TinyOS , Unison RTOS, DSPnano RTOS, nanoQplus, Contiki and Zephyr operating systems also use some components of IEEE 802.15.4 hardware and software. The standard defines two types of network node. The first one is the full-function device (FFD). It can serve as

5850-521: The use of relatively simple transceivers, while enabling application flexibility and adaptability. Key 802.15.4 features include: Devices are designed to interact with each other over a conceptually simple wireless network . The definition of the network layers is based on the OSI model ; although only the lower layers are defined in the standard, interaction with upper layers is intended, possibly using an IEEE 802.2 logical link control sublayer accessing

5928-425: The years, the Alliance's membership has grown to over 500 companies, including the likes of Amazon , Apple , Comcast , Google , Yandex , Ikea , and Samsung SmartThings . The CSA has four levels of membership: associate, adopter, participant, and promoter. Associate membership is free. However, it only allows the member to white-label certified products as well as use Alliance Certification trademarks for

6006-587: Was finalized in 2007. A Zigbee Pro device may join and operate on a legacy Zigbee network and vice versa. Due to differences in routing options, a Zigbee Pro device must become a non-routing Zigbee End Device (ZED) on a legacy Zigbee network, and a legacy Zigbee device must become a ZED on a Zigbee Pro network. It operates using the 2.4 GHz ISM band, and adds a sub-GHz band. Zigbee protocols are intended for embedded applications requiring low power consumption and tolerating low data rates . The resulting network will use very little power—individual devices must have

6084-466: Was released expanding the four PHYs available in the earlier 2006 version to six, including one PHY using direct sequence ultra-wideband (UWB) and another using chirp spread spectrum (CSS). The UWB PHY is allocated frequencies in three ranges: below 1 GHz, between 3 and 5 GHz, and between 6 and 10 GHz. The CSS PHY is allocated spectrum in the 2450 MHz ISM band. In April, 2009 IEEE 802.15.4c and IEEE 802.15.4d were released expanding

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