Transport channels are used as the basic transmission service offered by layer 1 to MAC. MAC will use transport channels to multiplex and demultiplex logical channels onto and from them. In contrast to logical channel types, referring to the type of information transmitted, transport channel types are used to indicate the transport characteristics. This means … Read more
Authentication and Access Control in Wimax Access control is the security mechanism to ensure that only valid users are allowed access to the network. In the most general terms, an access control system has three elements: (1) an entity that desires to get access: the supplicant, (2) an entity that controls the access gate: the … Read more
Logical channels are in a one-to-one fashion associated with radio bearers. Logical channel types are used to distinguish the type of information transmitted within the attached radio bearer. The two major groups of logical channel types are therefore control channels for signaling and traffic channels for IP user data. Currently the following logical channel types … Read more
SEATTLE—T-Mobile USA Inc. and its parent company, Deutsche Telecom A.G., have been ordered by the U.S. Department of Labor to pay $345,972 to a worker allegedly fired for being a whistle-blower. Bellevue, Wash.-based T-Mobile said it plans to appeal. The Department of Labor’s order resulted from an investigation into alleged violations of the whistleblower protection … Read more
How to Layer 2 Functions and Data Flow in LTE For layer 2 let us first take a look into the uplink. Data transmission is handled through the protocol stack according to the following flow: 1. Data is generated by either signaling control protocols (RRC, NAS) or by some application on the UE’s IP stack. … Read more
Different Tasks and States of RRC Protocol in LTE-EUTRAN The RRC protocol for EUTRAN is responsible for the basic configuration of the radio protocol stack. But one should note, that some radio management functions (scheduling, physical resource assignment for physical channels) are handled by layer 1 and layer 2 autonomously. MAC and layer 1 signaling … Read more
Radio Protocol Architecture in LTE The EUTRAN radio protocol model specifies the protocols terminated between UE and eNB. The protocol stack follows the standard guidelines for radio protocol architectures (ITU-R M1035) and is thus quite similar to the WCDMA protocol stack of UMTS. The protocol stack defines three layers: the physical layer (layer 1), data … Read more
What is SC-FDMA and how it works in LTE? One of the major drawbacks of an OFDMA system is, that the transformation of a complex symbol mapped sequence (e.g. BPSK, QPSK, etc.) onto a small set of subcarriers produces time sequences that have high PAPR (Peak-to-Average Power Ratio). PAPR is the ratio between the maximum … Read more
How Many Different Methods to Combine OFDMA for handle Multiuser System? Threre are four Different Methods to Combine OFDMA for handle Multiuser System. Plain OFDM: Normal LTE OFDM has no built-in multiple-access mechanism. This is suitable for broadcast systems like DVB-T/H which transmit only broadcast and multicast signals and do not really need an uplink … Read more