Active RFID TAGs system analysis of energy consumption as excitable linear bifurcation system

Active RFID TAG system can be represent as Voltage source (internal resistance), Parallel Resistor, Capacitor, and Inductance circuit. Linear bifurcation system explain Active RFID TAG system behavior for any initial condition V(t) and dV(t)/dt. Active RFID's Coil is a very critical element in Active RFID TAG functionality. Active RFID TAGs system energy consumption can be function of many variables : q(m), u(m), z(m), t(m), tms (m), when m is the number of TAG IDs which are uniformly distributed in the interval [0,1). It is very important to emphasis that basic Active RFID TAG, equivalent circuit is Capacitor (Cic), Resistor (Ric), L (RFID's Coil inductance as a function of overall Coil's parameters) all in parallel and Voltage generator Vs(t) with serial parasitic resistance. The Voltage generator and serial parasitic resistance are in parallel to all other Active RFID TAG's elements (Cic, Ric, and L (Coil inductance)). Optimization can be achieved by Coil's parameters inspection and System bifurcation controlled by them. Spiral, Circles, and other Active RFID phase system behaviors can be optimize for better Active RFID TAG performance and actual functionality. Active RFID TAG losses also controlled for best performance and maximum efficiency.

replaced. Battery outages in an active TAGs can result in expensive misreads. Active RFID TAGs may have all or some of the following features: Longest communication range of any TAG. The capability to perform independent monitoring and control. The capability of initiating communications. The capabilities of performing diagnostics. The highest data bandwidth. The active RFID TAGs may even be equipped with autonomous networking ; the TAGs autonomously determine the best communication path. Mainly active RFID TAGs have a built in power supply, such as battery, as well as electronics that perform specialized tasks. By By contrast, passive RFID TAGs do not have a power supply and must rely on the power emitted by a RFID Reader to transmit data. There is an arbitration while reading TAGs (TAGs anti collision problem). First identify and then read data stored in RFID TAGs. It is very important to read TAG IDs of all. The Anti collision protocol based on two methods: ALOHA and its variants and Binary tree search. ALOHA protocol reducing collisions by separating TAG responds by time (probabilistic and simple). TAG ID may not be read for a very long time. The Binary tree search protocol is deterministic in nature. Read all TAGs by successively querying nodes at a different levels of the tree with TAG IDs distributed on the tree based on there prefix. Guarantee that all TAGs IDs will be read within a certain time frame. The binary tree search procedure, however, uses up a lot of reader queries and TAG responses by relying on colliding responses of TAGs to determine which sub tree to query next. Higher energy consumption at readers and TAGs (If they are active TAGs). TAGs cant be assumed to be able to communicate with each other directly. TAGs may not be able of storing states of the arbitration process in their memory. There are three anti collision protocols: Alls include and combine ideas of a binary tree search protocol with frame slotted ALOHA, deterministic schemes, and energy aware. The first anti collision protocol is Multi Slotted (MS) scheme, multiple slots per query to reduce the chances of collision among the TAG responses. The second anti collision protocol is Multi Slotted with Selective sleep (MSS) scheme, using sleep commands to put resolved TAGs to sleep during the arbitration process. Both MS and MSS have a probabilistic flavor, TAGs choose a reply slot in a query frame randomly. The third anti collision protocol is Multi Slotted with Assigned slots (MAS), assigning TAGs in each sub tree of the search tree to a specific slot of the query frame. It's a deterministic protocol, including the replay behavior of TAGs. All three protocols can adjusting the frame size used per query. Maximize energy savings at the reader by reducing collisions among TAG responses. The frame size is also chosen based on a specified average time constraint within which all TAGs IDs must be read. The binary search protocols are Binary Tree (BT) and Query Tree (QT). Both work by splitting TAG IDs using queries from the reader until all TAGs are read. Binary Tree (BT) relies on TAGs remembering results of previous inquiries by the readers. TAGs susceptible to their power supply. Query Tree (QT) protocol, is a deterministic TAG anti collision protocol, which is memory less with TAGs requiring no additional memory except that required to store their ID. The approach to energy aware anti collision protocols for RFID systems is to combine the deterministic nature of binary search algorithms along with the simplicity of frame slotted ALOHA to reduce the number of TAG response collisions. The QT protocol relies on colliding responses to queries that are sent to internal modes of a tree to determine the location of TAG ID. Allow TAGs to transmit responses within a slotted time frame and thus, try to avoid collisions with responses from other TAGs. The energy consumption at the reader is a function of the number of queries it sends, and number of slots spent in the receive mode. Energy consumption at an active TAG is function of the number of queries received by the TAG and the number of responses it sends back. Neglect the energy spent in modes other than transmit and receive for simplicity. Assumption: Time slot in which a reader query or message is sent is equal to the duration as that of a TAG response. The   I get the expression for One active RFID TAG total energy consumption:

Active RFID TAG equivalent circuit
Active RFID TAG can be represent as a parallel Equivalent Circuit of Capacitor and Resistor in parallel with Supply voltage source (internal resistance).

F slots reader wait for response
One slot for a query from reader The Active RFID TAG Antenna can be represents as Parallel inductor to the basic Active RFID Equivalent Circuit. The simplified complete equivalent circuit of the label is as below:   Table 3.
Active RFID can be considered as Van der Pol's system. Van der Pol's equation provides an example of an oscillator with nonlinear damping, energy being dissipated at large amplitudes and generated at low amplitudes. Such systems typically posses limit cycles, sustained oscillations a round a state at which energy generation and dissipation balance. The basic Van der Pol's equation can be written in the form: It is necessary to examine the trajectories (V1,V2,t) of the non-autonomous Active RFID system in 2 xR R rather than the orbits in 2 R . Equivalently, we may consider the orbits of the Active RFID TAGs three dimensional autonomous system.

Active RFID TAG as a dynamic energy analysis
Active RFID equivalent circuit total TAG power is a summation of all element's power.  VV and the Quadratic terms are tiny, its tempting to neglect them altogether.

Active RFID TAG fixed points and linearization
If we do that, we obtain the linearized system. (1 ,2 ) 2 which "freezes" the unperturbed system and the autonomous system become :

Summery
Active RFID TAG system can be represent as Voltage source (internal resistance) , Parallel Resistor, Capacitor, and Inductance circuit. Linear bifurcation system explain Active RFID TAG system behavior for any initial condition V(t) and dV(t)/dt. Active RFID's Coil is a very critical element in Active RFID TAG functionality. Optimization can be achieved by Coil's parameters inspection and System bifurcation controlled by them. Spiral, Circles, and other Active RFID phase system behaviors can be optimize for better Active RFID TAG www.intechopen.com