Multiplexing and Access schemes

Multiplexing and Access Schemes

Mobiles new access schemes like to orthogonal- FDMA, Single carrier -FDMA, Interliver -FDMA and Multi- carrier - CDMA are important for the 4G access generation. FDMA is a multi users version who assignings subsets of subcarriers to industrial-OFDMA is used in mostly mobility mode of the IEEE 802.16, Wireless MAN standard.

• SC- FDMA is a frequency division multiple access schene. There TDMA, FDMA, CDMA, OFDMA, other mulgtiple access who deals with the assignment of multiple users to a shared communoication resourse.
• Multiple Carrier Code Division Multiple Access is a multiple access schene used in OFDM based telecommunicator.
• MC-CDMA spreads each user symbol in the frequency domain, according the code value. The code value different per subcarrier and per user.
• These access scheme offer the same efficiencues as older technologies as CDMA.

IPv6

• At present time that 4G deployed the process of IPv4 adderess exhaustion IPv4 provides approximatelly 4.3 billion addresses. The depletion of the IPv4 allocation pool has been a concern sicne the late 1980s.
• For the context of 4G. IPv6 is essential to support a large number of wireless devices.
• A method of sharing a limited mumber of adderesses among a larger group of devices, IPv6 removes the need for metwork address  translation rates in a larger part of the cell.
• A major issue in 4G access is to own IP address is to make  the high speed bit rates in a larger part of the cell.
• With IPv6, each devices will have its own IP address.
• IP access will allow everithing to talk to each other provided they follow the same protocol.