- It is point to point connection.
- The mesh topology has a direct connection between every pair of devices in the network.
- Communication becomes very simple because there is no competition for common line.
- If two device want to communicate, they do communication directly without involving other device.
Advantages of mesh topology
- The use of large number of links eliminates network congestion.
- If one link become unusable it does not disable the entire system.
Disadvantages of mesh topology
- The amount of required cabling is very high.
- As every node is connected to the other, installation and reconfiguration is very difficult.
- The amount of hardware required in this type of topology can make it expensive to implement.
- The object of any RFID system is to carry data in suitable transponders, generally known as tags, and to retrieve data, by machine-readable means, at a suitable time and place to satisfy particular application needs. Data within a tag may provide identification for an item in manufacture, goods in transit, a location, the identity of a vehicle, an animal or individual. By including additional data the prospect is provided for supporting applications through item specific information or instructions immediately available on reading the tag. For example, the colour of paint for a car body entering a paint spray area on the production line, the set-up instructions for a flexible manufacturing cell or the manifest to accompany a shipment of goods.
- A system requires, in addition to tags, a means of reading or interrogating the tags and some means of communicating the data to a host computer or information management system. A system will also include a facility for entering or programming data into the tags, if this is not undertaken at source by the manufacturer. Quite often an antenna is distinguished as if it were a separate part of an RFID system. While its importance justifies the attention it must be seen as a feature that is present in both readers and tags, essential for the communication between the two.
To understand and appreciate the capabilities of RFID systems it is necessary to consider their constituent parts. It is also necessary to consider the data flow requirements that influence the choice of systems and the practicalities of communicating across the air interface. By considering the system components and their function within the data flow chain it is possible to grasp most of the important issues that influence the effective application of RFID. However, it is useful to begin by briefly considering the manner in which wireless communication is achieved, as the techniques involved have an important bearing upon the design of the system components.
Areas of Application for RFID
-Library File Is Power Of Any Language Because It Will use More Fetures From Library And Will Solve Problem.
-In Simple Word You Have Used printf() , scanf() function In c So Where This Function Defined ? Answer is stdio.h file If You Want Use That Function Then Must Be use Library.
-You can Make Your Own Library Then Use It
- The physical layer is responsible for movement of individual bits from one hop (node) to the next.
---- ( Features / Responsibilities ) ----
Physical characteristics of interfaces and medium:
- Define the characteristics of the interface between device and transmission medium.
- Define type of transmission medium.
Representation of bits:
- Data consist of a stream of bits (sequence 0 or 1)
- Bit must be encoded into signal (electrical or optical)
- Number of bit sent each second is called transmission rate
Synchronization of bit:
- Sender and receiver clock must be synchronized used same bit rate.
- Point to point : dedicated link
- Multipoint: link is shared among several device
- Define how device are connected in network Bus, ring, mesh, star, hybrid
Define the direction of transmission between two device Simples, half duplex and full duplex
- Rumbaugh developed a technique that focused on analysis, design and implementation of the system. It is known as <>Object Modelling Technique.
OMT consists of 4 phases:
2. system design
3. object design
Analysis phase is composed of three sub models shown below:
1. Object Model: It captures the static aspect of the system
2. Dynamic Model: It captures the behavioral aspects of the object models and describes state of the objects.
3. Functional Model: It represents the functional aspects of the system in terms of operations defined in the classes.
- In the object model, the requirements are stated in the problem statement. The relevant classes along with inheritance relationships are extracted from this problem statement.
- The dynamic model identifies states and events in the classes identifies in object models. The functional model depicts the functionality of the system by creating data flow diagrams of the system in order to understand the processes.
System design phase:
- in this phase, a high level design is developed taking the implementation environment including DBMS and communication protocols into account.
Object design phase:
- The goal of this is to define the objects in detail. The algorithms and operations of the objects are defined in this phase. New objects may be identified to represent the intermediate functionality.
- Finally the objects are implemented following standards and guidelines.