In last couple of years micro-sensor development have seen a significant development which resulted in the wide use of Wireless Sensor Networks (WSNs) for remote monitoring. Sensor networks have a wide variety of applications in systems with vastly varying requirements and characteristics. The sensor networks can be used in,
LTE radio interface consists of 3 layers,
Layer 1 – Physical Layer
Physical layer offers data transport services to MAC layer.
Main functions of physical layer include: Mapping of transport channels on to the physical channels, forward error correction (FEC), Modulation & Coding etc.
Layer 2 Sublayer – Medium Access Control (MAC)
Last week, Sprint introduced Samsung Galaxy Victory 4G LTE for $99.99 with a new line or eligible upgrade and two-year service agreement. Galaxy Victory features Android 4.0, Ice Cream Sandwich, a 1.2GHz dual-core processor and 4-inch touchscreen display.
Additional features on Galaxy Victory include:
Samsung plans to launch the Galaxy Note II in the U.S. with five major carriers by mid-November. Then new model will be available with with AT&T, Sprint, T-Mobile, Verizon Wireless and U.S. Cellular. Optimized for the LTE and HSPA+ 42 networks, the Galaxy Note II has Android 4.1 Jelly Bean and combines some of the best capabilities of the Galaxy S III with an enhanced S Pen and new S Pen apps with a larger screen yet in a thinner, lighter form factor.
LTE Medium Access Control (MAC) is a layer 2 protocol and provides data transfer and radio resource allocation services to upper layers. It performs scheduling of the data according to priorities, and multiplexing data to physical layer transport blocks. RRC layer controls configuration of MAC sublayer. In E-UTRA, there are two MAC entities, one in the UE and other one in the eNB.
OFDM stands for Orthogonal Frequency Division Multiple Access. OFDM is a multicarrier technique in which information to be transmitted is mapped onto several parallel orthogonal sub-carriers. OFDM when combined with Frequency Division Multiple Access (FDMA) or Time Division Multiple Access (TDMA) or a mix of both, can be used for multiple access.
LTE Radio Link Control (RLC) protocol is one of eNB’s Layer 2 sublayers that also consist of Medium Access Control (MAC) and Packet Data Convergence Protocol (PDCP) protocols. RLC layer transfers upper layer (PDCP) PDUs and supports protocol error detection & recovery functions.
With 3GPP Rel-6 radio resource management and mobility management functions primarily reside in Radio Network Controller (RNC) while radio protocols are handled by NodeB. The 3GPP Rel-8 evolves the network in flat architecture.
Many of the targets implied that a flat architecture would need to be developed for LTE so that less number of nodes will be involved and hence reduces latencies and improves performance.
This week, Apple announced much awaited iPhone 5 that supports LTE technology. The thinnest and lightest iPhone ever is completely redesigned and has stunning new 4-inch Retina display, an Apple-designed A6 chip for fast performance and mobile operating system iOS 6 with over 200 new features.
LTE capable iPhone 5 is 8 percent thinner and 20 percent lighter than iPhone 4S.The new iPhone has 4-inch Retina display, an A6 chip and mobile operating system iOS 6 with over 200 new features.
iPhone 5 comes in either white & silver or black & slate, and will be available in the US for a suggested retail price of $199 (US) for the 16GB model and $299 (US) for the 32GB model and $399 (US) for the 64GB model.