The procedures for the Non Access Stratum, especially power management procedures are substantially similar to UMTS. Main change is that the UMTS EPS allows concatenation certain procedures to allow faster creation of connection and media. Create MME UE context, when the UE is on and attaches to the network. Assign a unique ID called SAE … Read more
LTE core network also called EPC in SAE is responsible for the complete control of the UE and the creation of media. The main logical nodes LTE EPC are: • PDN Gateway (P-GW) • Serving Gateway (S-GW) • Mobility Management Entity (MME) PCRF of LTE Core Network The political control and charging rules is responsible … Read more
EPS provides the user with a PDN IP connectivity for Internet access and for the operation of services such as Voice over IP (VoIP). An EPS bearer is usually associated with a QoS. Multiple carriers may be set for a user, in order to provide different QoS flows and connectivity to different PDNs. For example, … Read more
Spatial Multiplexing In a multipath environment, the data rate increase due to MIMO is equal to the number of MIMO antennas. Rather than to transmit the same bit of more than two antennas, the Spatial Multiplexing method sends a data bit from the first antenna, and another bit of the second antenna at the same … Read more
Make use of a number of receive antennas that are well separated (coherence distance) to generate independent receptions of the transmitted signal. Selection diversity: choose received signal with largest received power, S/N, etc. Switched diversity: choose alternate antenna if signal falls below a certain threshold. Linear combining: linearly combine a weighted replica of all received … Read more
We know that we normally have several independent paths from TX to Rx of different lengths, these are affected and delayed differently, Signals that start out together at the transmitter will be separated in time when they reach the receiver Diversity doesn’t work with Line of Sight, This is exploiting Multipath rather than fighting it … Read more
RADIUS Protocol Stack in Wimax The RADIUS protocol stack in WiMAX is a vital authentication and authorization framework, facilitating secure access and management of WiMAX network resources. RADIUS is a protocol that enables a single server to become responsible for all remote access authentication, authorization, and auditing (or accounting) services. RADIUS functions as a client/server … Read more
IMS means IP Multimedia Subsystem is an essential part of the all-IP UMTS architecture and Relevant for WiMAX for the same usage and also for WiMAX to UMTS Interworking. This is part of the WiMAX Forum architecture. IP Multimedia Subsystem (IMS) is a Service Delivery Architecture and standardized architecture to provide Internet Protocol (IP)-based mobile … Read more
IP Multicast Service Models Having Three Multicast Any-Source Multicast (ASM) Source-Filtered Multicast (SFM) and Source-Specific Multicast (SSM) which work as below. Any-Source Multicast (ASM) Destination ‘multicast’ address only defines ‘Group’ membership Will accept from ‘any source’ (unicast) First and oldest model, defined in RFC 1112 Source-Filtered Multicast (SFM) Destination ‘multicast’ address only defines ‘Group’ membership … Read more
When sending the same data to multiple receivers, rather than send multiple copies all the way from sender to all the receivers, just send one copy and duplicate where paths diverge Better bandwidth utilisation Less host/router processing Receivers’ addresses may be unknown A possible thing to use for IPTV over WiMAX. Multicast Advantages Enhanced Efficiency: … Read more