Alice in Telecomland

Witricity, standing for wireless electricity, is a term used to describe the ability to provide electricity to remote objects without wires. Witricity is nothing but wireless electricity used to transmit electrical energy from one object to another without using wires. due to witricity some device will not require batteries to operate.WiTricity is based on strong coupling between electromagnetic resonant objects .This differs from other methods like simple induction, microwaves, or air ionization.

Basic principle:

Consider two self resonating copper coils of same resonating  frequency  with  a  diameter  20  inches  each. One  copper wire  is  connected  to  the  power  source  (WiTricity  transmitter), while the other copper wire is connected to the device (WiTricity Receiver).  The  electric  power  from  the  power  source  causes  the  copper  coil connected  to  it  to  start  oscillating  at  a  particular  (MHz)  frequency. Subsequently,  the space around  the copper coil gets  filled with non-magnetic  radiations.  This  generated magnetic  field  further  transfers the power  to  the other copper  coil  connected  to  the  receiver. Since this coil is also of the same frequency, it starts oscillating at the same frequency as  the  first coil. This  is known as  ‘coupled resonance’ and is the principle behind WiTricity.

The system consists of transmitters and receivers having magnetic loop antennas tuned to same frequency.The receiving devices must be no more than about a quarter wavelength from the transmitter .During normal operation, an antenna emits electromagnetic fields into the surrounding nearfield region, then a portion of the field energy decays since it is re-absorbed by the antenna, while the remainder is radiated into the environment as EM waves.Non-radiative wireless power would have limited range, and the range would be shorter for smaller-size receivers .

It has been more than 100 years since this technology was initially discovered. witricity is not a new concept. it is safe and sound for human beings as well. We need it badly because of its plenty of merits.This could be useful to power consumer and industrial electronics like cell phones, laptops, etc

RFID stands for Radio Frequency Identification. It is a method of identifying unique items using radio waves. It can be applied to or incorporated into a product, animal, or person for the purpose of identification and tracking using radio waves .Typical RFID systems are made up of 2 major components: readers and tags. The reader, sometimes called the interrogator, sends and receives RF data to and from the tag via antennas. A reader may have multiple antennas that are responsible for sending and receiving the radio waves. The tag, or transponder, is made up of the microchip that stores the data, an antenna, and a carrier to which the chip and antenna are mounted.

There are many different versions of RFID that operate at different radio frequencies. The choice of frequency is dependent on the requirements of the application. Three primary frequency bands have been allocated for RFID use.

Low Frequency (125/134KHz) – Most commonly used for access control and asset tracking.
Mid-Frequency (13.56 MHz) – Used where medium data rate and read ranges are required.
Ultra High-Frequency (850 MHz to 950 MHz and 2.4 GHz to 2.5 GHz) – offer the longest read ranges and high reading speeds.

RFID technologies cannot reliably cover areas wider than 4 to 5 feet, unsuitable for wide openings that are the norm in manufacturing, distribution and store receiving dock environments. Since UHF (Ultra High Frequency) can cover portals up to 9 feet wide it is gaining industry support as the choice bandwidth for inventory tracking applications including pallets and cases.

RFID tags are further broken down into two categories:

Active RFID Tags are battery powered. They broadcast a signal to the reader and can transmit over the greatest distances 100+ feet and are used to track high value goods like vehicles and large containers of goods. Shipboard containers are a good example of an active RFID tag application.

Passive RFID Tags do not contain a battery. Instead, they draw their power from the reader. The reader transmits a low power radio signal through its antenna to the tag, which in turn receives it through its own antenna to power the integrated circuit (chip). The tag will briefly converse with the reader for verification and the exchange of data. As a result, passive tags can transmit information over shorter distances (10 feet or less) than active tags. They have a smaller memory capacity and are considerably lower in cost making them ideal for tracking lower cost items.

There are two basic types of chips available on RFID tags, Read-Only and Read-Write. Read only chips are programmed with unique information stored on them during the manufacturing process. The information on read-only chips can never be changed. With Read-Write chips, the user can add information to the tag or write over existing information when the tag is within range of the reader. Read-Write chips are more expensive that Read Only chips. Another method used is something called a “WORM” chip (Write Once Read Many). It can be written once and then becomes “Read Only” afterwards.

Radio Frequency Identification (RFID) technology has been attracting considerable attention with the expectation of improved supply chain visibility for both suppliers and retailers.RFID is expected to provide huge advantages to manufacturers by offering the tools to better plan production and respond more quickly to market demand. It will facilitate automation of inventory counts and speed shipping and receiving at the distribution level.

LTE (Long Term Evolution) is the step toward the 4G, designed to increase the capacity and speed of mobile telephone networks. LTE is a set of enhancements to the Universal Mobile Telecommunications System. The LTE specification provides downlink peak rates of at least 100 Mbps, an uplink of at least 50 Mbit/s and RAN round-trip times of less than 10 milli sec. LTE supports scalable carrier bandwidths, from 20 MHz down to 1.4 MHz and supports both Frequency Division Duplexing and Time Division Duplexing.

In addition to enabling fixed to mobile migrations of Internet applications such as Voice over IP (VoIP), video streaming, music downloading, mobile TV and many others, LTE networks will also provide the capacity to support an explosion in demand for connectivity from a new generation of consumer devices tailored to those new mobile applications. 3GPP LTE radio technology is optimized to enhance networks by enabling significant new high capacity mobile broadband applications and services, whilst providing cost efficient ubiquitous mobile coverage.

LTE characteristics include:

• Peak LTE throughputs (high spectral efficiency)

• Increased Spectrum efficiency

• Ultra low Latency

- Less than 10 msec for round-trip delay (RTD) from UE to server

- Reduced call setup times (50-100ms)

- wired user experience

• Capacity per cell

- 200 users for 5 MHz, 400 users in larger spectrum allocations

• Flexible spectrum use maximizes flexibility

- 1.4, 3/3.2, 5, 10, 15, 20 MHz

- All frequencies of IMT-2000: 450 MHz to 2.6 GHz

Another key driver behind LTE is the reduction of the cost per byte, which is expected to decrease by a factor of six compared with HSPA today. LTE has multiple inputs and multiple output & collaborative MIMO. Alcatel Lucent, Nokia & Motorola are working to make further enhancements to make LTE successful in industry and to do further enhancements for 4G.