4G Cell Broadband - LTE Network Architecture and Protocol Stack

ABSTRCT

The objective of the LTE typical ?custom pdu will be to generate technical specs to get a new radio-access technologies geared to greater facts charges, low latency and greater spectral performance. The spectral efficiency concentrate on for the LTE program is a few to 4 situations better as opposed to existing HSPA program. These aggressive spectral performance targets need making use of the know-how envelope by utilizing highly developed air-interface methods for example low-PAPR orthogonal uplink numerous entry determined by SC-FDMA(single-carrier frequency division various entry) MIMO multiple-input multiple-output multi-antenna technologies, inter-cell interference mitigation methods, lower latency channel structure and single-frequency community (SFN) broadcast. The researchers and engineers engaged on the normal arrive up with new innovative technology proposals and ideas for technique overall performance enhancement. Due to the really intense common advancement routine, these scientists and engineers are generally not able to publish their proposals in conferences or journals, and so forth. From the specifications enhancement period, the proposals endure comprehensive scrutiny with numerous sources analyzing and simulating the proposed technologies from technique efficiency enhancement and implementation complexity views. As a result, just the highest-quality proposals and concepts last but not least make in to the regular.

Keywords and phrases: LTE Architecture, UDP, GDP, MIMO, MIME, MCCH, MBMS, QOS

1. INTRODUCYION

The LTE community architecture is intended with all the aim of supporting packet-switched targeted traffic with seamless mobility, quality of provider (QoS) and minimum latency. A packet-switched technique enables for that supporting of all companies such as voice by way of packet connections. The end result in a very remarkably simplified flatter architecture with only two varieties of node specifically evolved Node-B (eNB) and mobility administration entity/gateway (MME/GW). This is certainly in distinction to quite a few a lot more network nodes in the present-day hierarchical network architecture from the 3G process. Just one major alter is the fact the radio network controller (RNC) is eliminated from the details path and its features are actually included in eNB. A few of the advantages of the solitary node during the entry network are minimized latency plus the distribution from the RNC processing load into several eNBs. The elimination with the RNC in the obtain community was possible partly since the LTE system won't support macro-diversity or soft-handoff.

2. LTE Network ARCHITECTURE

Many of the community interfaces are dependant on IP protocols. The eNBs are interconnected through an X2 interface also to the MME/GW entity via an S1 interface as demonstrated in Figure1. The S1 interface supports a many-to-many connection involving MME/GW and eNBs.

The useful split concerning eNB and MME/GW is demonstrated in Figure 2 Two sensible gateway entities namely the serving gateway (S-GW) and also the packet data network gateway (P-GW) is described. The S-GW acts for a neighborhood mobility anchor forwarding and obtaining packets to and from the eNB serving the UE. The P-GW interfaces with exterior packet data networks (PDNs) like the Internet plus the IMS. The P-GW also performs numerous IP features which include handle allocation, policy enforcement, packet filtering and routing.

The MME is actually a signaling only entity and therefore consumer IP packets will not go through MME. A bonus of a different community entity for signaling is the fact that the network capability for signaling and targeted traffic can improve independently. The leading features of MME are idle-mode UE arrive at means including the handle and execution of paging retransmission, monitoring spot checklist administration, roaming, authentication, authorization, P-GW/S-GW range, bearer administration including committed bearer institution, stability negotiations and NAS signaling, and so on.

Advanced Node-B implements Node-B features as well as protocols historically applied in RNC. The leading features of eNB are header compression, ciphering and dependable shipping of packets. Over the command facet, eNB incorporates features for instance admission manage and radio source administration. A few of the benefits of a solitary node inside the accessibility network are lessened latency along with the distribution of RNC the community facet are actually terminated in eNB.

Figure one: Network Architecture

Determine two: Purposeful split among eNB and MME/GW.

2.one PROTOCOL STACK AND CONYTOL Airplane

The consumer aircraft protocol stack is specified in Figure 3.We notice that packet details convergence protocol (PDCP) and radio link management (RLC) layers historically terminated in RNC on Figure 4 displays the regulate plane protocol stack.

Figure three: Consumer aircraft protocol.

Determine four: Management plane protocol stack.

We be aware that RRC features historically carried out in RNC has become incorporated into eNB. The RLC and MAC layers carry out the exact same capabilities since they do with the consumer airplane. The functions carried out because of the RRC include things like method data broadcast, paging, radio bearer control, RRC connection administration, mobility functions and UE measurement reporting and control. The non-access stratum (NAS) protocol terminated while in the MME on the community side and within the UE to the terminal facet performs capabilities for example EPS (evolved packet program) bearer management, authentication and safety control, and many others.

The S1 and X2 interface protocol stacks are shown in Figures two.five and a pair of.six respectively.We take note that related protocols are utilized on these two interfaces. The S1 person airplane interface (S1-U) is defined among the eNB and the S-GW. The S1-U interface utilizes GTP-U (GPRS tunneling protocol - person details tunneling) on UDP/IP transport and gives non-guaranteed shipping and delivery of person plane PDUs in between the eNB as well as S-GW. The GTP-U is usually a rather very simple IP centered tunneling protocol that allows lots of tunnels between each and every list of conclude factors. The S1 control airplane interface (S1-MME) is defined as currently being in between the eNB as well as MME. Comparable to the user plane, the transportation community layer is developed on IP transportation and to the reliable