LEBÉE Marie-Hélène PERALTA Philippe A1B IEEE j standard

Why this subject? Wireless technologies are more and more used nowadays. The j standard is relative to the technology of wireless local area networks That’s why we were interested on it. Wireless technologies are more and more used nowadays. The j standard is relative to the technology of wireless local area networks. That’s why we were interested on it.

How we have worked We have organised the work in four parts: -research-reading-selection-redaction We have separated the work in two between us

1. Presentation of Wi-Fi 2. The standard 2.1 The OSI model 2.2 The physical layer 2.2 The physical layer 2.3 The data link layer 2.3 The data link layer LLC MAC 3. The different specifications of the standard 4. The j standard 4.1 The particular case of Japan 4.1 The particular case of Japan 4.2 Modulation technique for transmission: OFDM 4.2 Modulation technique for transmission: OFDM 5. Conclusion

Presentation of Wi-Fi Presentation of Wi-Fi Technology of WLAN is based on the IEEE specifications Firstly created for internal networks Used for Internet access, gaming, and basic connectivity of consumer electronics

The standard

The OSI model Open Systems Interconnection Layered abstract description for communications and computer network protocol design The IEEE standard defines only the data link layer and the physical layer

The physical layer The physical layer Provides the means of transmitting raw bits Performs services requested by the data link layer Defines all the electrical and physical specifications for devices

The data link layer The data link layer Transfers data between adjacent network nodes Provides the functional and procedural means to transfer data Provides the means to detect and possibly correct errors that may occur in the physical layer May be split into a MAC layer and a LLC layer

The most important specifications The most important specifications In 1999 two extensions to were approved: a (5 GHz, 54 Mbps) a (5 GHz, 54 Mbps) b (2.4 GHz, 11 Mbps) b (2.4 GHz, 11 Mbps) In 2003: g (2.4 GHz, 54 Mbps) g (2.4 GHz, 54 Mbps) j is an extension of a

The j standard

The particular case of Japan j was: Finalized in 2004 Finalized in 2004 Elaborated specially for the Japanese market Elaborated specially for the Japanese market Works in a band of frequencies centered around 5 GHz to conform to the Japanese rules

Modulation technique for transmission: OFDM Orthogonal frequency-division multiplexing Divides the available spectrum into 52 orthogonal sub-carriers OFDM modulation and demodulation are typically implemented using digital filter banks generally using the Fast Fourier Transform (FFT).

Difficulties we have met Documents were hard to find Some documents were too technical

Conclusion The complexity of access to the licenses on the 5 GHz band in Japan did not make a standard popular as much as expected So, a new specification j appeared, with a limitation at 4.9 GHz Finally if the access to the 2.4 GHz and 5 GHz on the same peripheral requires a technological adaptation, the operation is simplified between the 4.9 GHz and 5 GHz, which makes it possible to develop peripherals which will accept the two frequencies without rupture

The end Thank you for your attention! Thank you for your attention!