Free space indicates an ideal, even, and isotropic medium of space. When electromagnetic waves are transmitted in this medium, no reflection, refraction, scattering, or absorption occurs. Propagation losses are caused only by the energy spread of electromagnetic waves. Satellite communication and microwave line-of-sight (LOS) communication are typical examples of free space propagation. In certain conditions, … Read more
Shadow fading indicates the fading brought by obstruction due to a building or a natural feature. Shadow fading changes slowly, and is thus called “slow fading”. Statistics repeatedly show that the median levels of received signals follow log-normal distribution with the time and location at a certain distance. Fading caused by location (mainly from obstruction) … Read more
Power boosting in LTE is mainly perform on the Reference signal. However, since the radio power is shared equally by all Resources element, the power allocation for each RE is fixed. By increasing the number of Resources element being used as Reference Signal, the RS can be “boosted’ by 2x (3dB), 3x (4.7dB) or 4x … Read more
Here I write on simple how guard band requirement for LTE for 2 option. Guard band requirement LTE verses GSM and guard band requirement LTE FDD verse LTE TDD Guard Band Requirement: LTE-FDD vs GSM/UMTS Configuration is simpler for FDD based systems because both LTE FDD and its neighboring technologies are based on frequency duplex … Read more
Here I write down one basic idea of Spectrum reframing in LTE and why operators require spectrum reframing for LTE. Operators worldwide are looking forward to new LTE technologies deployment but not every one of them possess brand new spectrum required for LTE deployment. As a result, many networks are expected to perform some level … Read more
Choosing which frequency band to operate a LTE network is one of the most critical decision. Operator has to make when it comes to capacity planning. The frequency propagation and penetration characteristics will determine the number of sites that need to be built in order to cover the designated area chosen by the Operator. This … Read more
CN (SAE called EPC) is responsible for the overall monitoring of the UE and the establishment media. Main logical nodes of the EPC are: PDN Gateway (P-GW) Serving GateWay (S-GW) Mobility Management Entity (MME) Evolved Serving Mobile Location Centre (E-SMLC) In addition to these nodes, EPC also includes other logical nodes and functions like a … Read more
NAS procedures, especially procedures for managing connections, essentially similar to UMTS. Main change UMTS is that the EPS allows the union of certain procedures to ensure a more rapid establishment of communication and media. MME creates a context of the UE, when the UE is turned on and attaches to the network. It allocates a … Read more
LTE access network and E-UTRAN, the network comprises a eNodeBs, as shown in Fig. For the normal user traffic (as opposed to transmission), there is no centralized controller in E-UTRAN, thus, E-UTRAN architecture is called flat. The eNodeBs are usually inter-connected together through an interface known as X2, and the EPC interface through S1 – … Read more