4G Mobile Broadband - LTE Network Architecture and Protocol Stack

The intention of the LTE popular is to create specifications for a brand new radio-access technology geared to better records rates, low latency and extra spectral performance. The spectral performance goal for the LTE gadget is three to four instances higher than the modern HSPA gadget.

These competitive spectral efficiency targets require the usage of the technology envelope by using using advanced air-interface techniques consisting of low-PAPR orthogonal uplink more than one get right of entry to primarily based on SC-FDMA(single-provider frequency department a couple of get right of entry to) MIMO a couple of-enter more than one-output multi-antenna technology, inter-cellular interference mitigation strategies, low latency channel structure and unmarried-frequency network (SFN) broadcast.

The researchers and engineers operating on the usual come up with new revolutionary era proposals and ideas for gadget overall performance improvement. Due to the noticeably competitive fashionable development schedule, these researchers and engineers are generally unable to submit their proposals in conferences or journals, etc. Architecture Services in Habibpur In the standards development phase, the proposals go through extensive scrutiny with a couple of assets comparing and simulating the proposed technology from machine performance improvement and implementation complexity views. Therefore, best the very best-first-class proposals and thoughts ultimately make into the usual.

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

1. INTRODUCYION

The LTE network structure is designed with the goal of supporting packet-switched visitors with seamless mobility, fine of service (QoS) and minimum latency. A packet-switched technique permits for the supporting of all offerings along with voice via packet connections. The bring about a fairly simplified flatter structure with best two forms of node specifically advanced Node-B (eNB) and mobility control entity/gateway (MME/GW). This is in comparison to many extra community nodes in the present day hierarchical network architecture of the 3G system.

One foremost change is that the radio network controller (RNC) is removed from the facts course and its capabilities are actually integrated in eNB. Some of the advantages of a single node in the get entry to community are decreased latency and the distribution of the RNC processing load into a couple of eNBs. The removal of the RNC inside the get admission to community changed into possible partly because the LTE system does now not support macro-variety or smooth-handoff.

2. LTE NETWORK ARCHITECTURE

All the community interfaces are based totally on IP protocols. The eNBs are interconnected by an X2 interface and to the MME/GW entity by means of an S1 interface as proven in Figure1. The S1 interface helps a many-to-many courting among MME/GW and eNBs.

The purposeful cut up between eNB and MME/GW is shown in Figure 2 Two logical gateway entities specifically the serving gateway (S-GW) and the packet records network gateway (P-GW) is defined. The S-GW acts as a neighborhood mobility anchor forwarding and receiving packets to and from the eNB serving the UE. Civil Work Services in Noida Phase-2 The P-GW interfaces with external packet facts networks (PDNs) which include the Internet and the IMS. The P-GW also performs several IP capabilities along with address allocation, coverage enforcement, packet filtering and routing.

The MME is a signaling only entity and therefore person IP packets do now not undergo MME. An gain of a separate community entity for signaling is that the community ability for signaling and site visitors can grow independently. The essential functions of MME are idle-mode UE attain potential along with the manipulate and execution of paging retransmission, tracking vicinity listing control, roaming, authentication, authorization, P-GW/S-GW choice, bearer management including committed bearer status quo, safety negotiations and NAS signaling, and so on.

Evolved Node-B implements Node-B capabilities in addition to protocols historically implemented in RNC. The most important capabilities of eNB are header compression, ciphering and reliable transport of packets. On the manipulate aspect, eNB contains functions consisting of admission manipulate and radio resource control. Some of the advantages of a unmarried node in the get admission to community are decreased latency and the distribution of RNC the network side at the moment are terminated in eNB.

Figure 1: Network Architecture

Figure 2: Functional split between eNB and MME/GW.

2.1 PROTOCOL STACK AND CONYTOL PLANE

The person plane protocol stack is given in Figure three.We notice that packet statistics convergence protocol (PDCP) and radio link manipulate (RLC) layers traditionally terminated in RNC on Figure 4 suggests the manage plane protocol stack.

Figure three: User aircraft protocol.

Figure four: Control aircraft protocol stack.

We note that RRC capability historically applied in RNC is now included into eNB. The RLC and MAC layers perform the equal capabilities as they do for the user plane. The functions done by the RRC consist of gadget statistics broadcast, paging, radio bearer manage, RRC connection management, mobility features and UE measurement reporting and manage. The non-access stratum (NAS) protocol terminated in the MME at the community facet and at the UE on the terminal aspect plays functions including EPS (advanced packet gadget) bearer management, authentication and safety manage, and so forth.

The S1 and X2 interface protocol stacks are proven in Figures 2.Five and a pair of.6 respectively.We word that similar protocols are used on those interfaces. The S1 person plane interface (S1-U) is described between the eNB and the S-GW. The S1-U interface uses GTP-U (GPRS tunneling protocol - consumer records tunneling) on UDP/IP shipping and gives non-assured delivery of person plane PDUs between the eNB and the S-GW. The GTP-U is a quite simple IP based totally tunneling protocol that permits many tunnels among every set of cease factors. Interior Designing Services in Haldoni More The S1 control plane interface (S1-MME) is defined as being between the eNB and the MME. Similar to the person aircraft, the transport network layer is built on IP delivery and for the reliable

Figure 5: S1 interface user and control planes.

Figure 6: X2 interface user and control planes.

Transport of signaling messages SCTP (move manipulate transmission protocol) is used on top of IP The SCTP protocol operates analogously to TCP ensuring reliable, in-sequence shipping of messages with congestion control. The software layer signaling protocols are referred to as S1 software protocol (S1-AP) and X2 utility protocol (X2-AP) for S1 and X2 interface control planes respectively.

3. QOS AND BEARER SERVICE ARCHITECTURE

Applications which includes VoIP, net surfing, video telephony and video streaming have unique QoS needs. Therefore, an essential feature of any all-packet community is the supply of a QoS mechanism to enable differentiation of packet flows based totally on QoS necessities. In EPS, QoS flows called EPS bearers are mounted among the UE and the P-GW as proven in Figure 7. A radio bearer transports the packets of an EPS bearer between a UE and an eNB. Each IP float (e.G. VoIP) is associated with a extraordinary EPS bearer and the network can prioritize traffic thus.

Figure 7: EPS bearer service structure.

When receiving an IP packet from the Internet, P-GW plays packet class based on sure predefined parameters and sends it the suitable EPS bearer. Based at the EPS bearer, eNB maps packets to an appropriate radio QoS bearer. There is one-to-one mapping among an EPS bearer and a radio bearer.

4. LAYER 2 STRUCTURE

The layer 2 of LTE includes 3 sub layers specifically medium get right of entry to control, radio link manipulate (RLC) and packet facts convergence protocol (PDCP). The provider get right of entry to factor (SAP) among the physical (PHY) layer and the MAC sub layer provide the shipping channels whilst the SAP among the MAC and RLC sub layers offer the logical channels. The MAC sub layer performs multiplexing of logical channels on to the shipping channels.

The downlink and uplink layer 2 systems are given in Figures eight and 9 respectively. The distinction between downlink and uplink systems is that within the downlink, the MAC sub layer additionally handles the priority among UEs in addition to priority handling most of the logical channels of a single UE. architecture Services in Noida Phase-2 The different functions done by using the MAC sub layers in both downlink and uplink consist of mapping among the logical and the delivery channels.
Multiplexing of RLC packet statistics devices (PDU), padding, delivery layout selection and hybrid ARQ (HARQ).

The main services and features of the RLC sub layers consist of segmentation, ARQ in-collection shipping and copy detection, and so on. The in-sequence shipping of higher layer PDUs isn't always guaranteed at handover. The reliability of RLC may be configured to either well known mode (AM) or un-well known mode (UM) transfers. The UM mode can be used for radio bearers that can tolerate a few loss. In AM mode, ARQ functionality of RLC Retransmits transport blocks that fail recovery by way of HARQ. The healing at HARQ can also fail due to hybrid ARQ NACK to ACK errors or due to the fact the most range of retransmission attempts is reached. In this example, the relevant transmitting ARQ entities are notified and ability retransmissions and re-segmentation can be initiated.

Figure 8: Downlink layer 2 shape.

Figure nine: Uplink layer 2 shape.

The PDCP layer performs features inclusive of header compression and decompression, ciphering and in-collection shipping and replica detection at handover for RLCAM, and so on. The header compression and decompression is executed the use of the strong header compression (ROHC) protocol. 5.1 Downlink logical, transport and bodily channels

4.1 DOWNLINK LOGICAL, TRANSPORT AND PHYSICAL CHANNELS

The relationship among downlink logical, delivery and bodily channels is proven in Figure 10. A logical channel is described by way of the kind of information it providers. The logical channels are further divided into control channels and site visitors channels. The manipulate channels deliver control-plane information, at the same time as traffic channels deliver consumer-plane statistics.

In the downlink, five manipulate channels and site visitors channels are defined. The downlink manage channel used for paging statistics transfer is known as the paging manage channel (PCCH). This channel is used whilst the network has no expertise approximately the vicinity cellular of the UE. The channel that contains machine manage information is referred to as the printed control channel (BCCH). Two channels specifically the common manage channel (CCCH) and the committed manage channel (DCCH) can convey records between the community and the UE. The CCCH is used for UEs that have no RRC connection at the same time as DCCH is used for UEs that have an RRC connection. The control channel used for the transmission of MBMS manage data is called the multicast control channel (MCCH). The MCCH is used by best the ones UEs receiving MBMS.

The two site visitors channels in the downlink are the committed traffic channel (DTCH) and the multicast traffic channel (MTCH). A DTCH is a point-to-factor channel dedicated to a unmarried UE for the transmission of user information. An MTCH is a factor-to-multipoint channel used for the transmission of user visitors to UEs receiving MBMS. The paging manage channel is mapped to a shipping channel called paging channel (PCH). The PCH supports discontinuous reception (DRX) to enable UE energy saving. A DRX cycle is indicated to the UE by using the community. The BCCH is mapped to both a transport channel called a printed channel (BCH) or to the downlink shared channel (DLSCH).

Figure 10: Downlink logical, shipping and bodily channels mapping.

The BCH is characterised by way of a set pre-defined format as this is the primary channel UE gets after acquiring synchronization to the mobile. The MCCH and MTCH are either mapped to a transport channel known as a multicast channel (MCH) or to the downlink shared channel (DL-SCH). The MCH helps MBSFN combining of MBMS transmission from more than one cells. The other logical channels mapped to DL-SCH consist of CCCH, DCCH and DTCH. The DL-SCH is characterised through support for adaptive modulation/coding, HARQ, energy manipulate, semi-static/dynamic resource allocation, DRX, MBM Transmission and multi antenna technologies. All the 4-downlink transport channels have the requirement to be broadcast in the complete coverage place of a cellular.

The BCH is mapped to a bodily channel known as bodily broadcast channel (PBCH), that's transmitted over four sub frames with 40 ms timing interval. Fabrication Services in Greater Noida The forty ms timing is detected blindly with out requiring any explicit signaling. Also, each sub body transmission of BCH is self-decodable and UEs with accurate channel situations might not need to anticipate reception of all the four sub frames for PBCH interpreting. The PCH and DL-SCH are mapped to a physical channel known as bodily downlink shared channel (PDSCH). The multicast channel (MCH) is mapped to physical multicast channel (PMCH), that's the multi-mobile MBSFN transmission channel.

The three stand-on my own bodily manage channels are the physical manage format indicator channel (PCFICH), the bodily downlink control channel (PDCCH) and the bodily hybrid ARQ indicator channel (PHICH). The PCFICH is transmitted every sub frame and carries facts at the variety of OFDM symbols used for PDCCH. The PDCCH is used to tell the UEs approximately the aid allocation of PCH and DL-SCH in addition to modulation, coding and hybrid ARQ statistics related to DL-SCH. A most of 3 or 4 OFDM symbols can be used for PDCCH. With dynamic indication of number of OFDM symbols used for PDCCH through PCFICH, the unused OFDM symbols most of the three or four PDCCH OFDM symbols can be used for information transmission. The PHICH is used to carry hybrid ARQ ACK/NACK for uplink transmissions.

Four.2 UPLINK LOGICAL, TRANSPORT AND PHYSICAL CHANNELS

The relationship among uplink logical, delivery and bodily channels is proven in Figure 2.Eleven. In the uplink two manipulate channels and a unmarried traffic channel is described. As for the downlink, common control channel (CCCH) and dedicated manage channel (DCCH) are used to carry information between the community and the UE. The CCCH is used for UEs having no RRC connection while DCCH is used for UEs having an RRC connection. Similar to downlink, devoted traffic channel (DTCH) is a point-to-point channel dedicated to a single UE for transmission of person data. All the three uplink logical channels are mapped to a transport channel named uplink shared channel (UL-SCH). The UL-SCH supports adaptive modulation/coding, HARQ, power manipulate and semi-static/dynamic aid allocation.

Another delivery channel defined for the uplink is referred to as the random get admission to channel (RACH), which may be used for transmission of restricted manage records from a UE with possibility of collisions with transmissions from different UEs. The RACH is mapped to bodily random get entry to channel (PRACH), which includes the random access preamble.

The UL-SCH delivery channel is mapped to bodily uplink shared channel (PUSCH). A stand-on my own uplink physical channel called physical uplink control channel (PUCCH) is used to hold downlink channel first-class indication (CQI) reports, scheduling request (SR) and hybrid ARQ ACK/NACK for downlink transmissions.

5. PROTOCOL STATES AND STATES TRANSITIONS

In the LTE system, radio resource control (RRC) states specifically RRC IDLE and RRC CONNECTED states are defined as depicted in Figure 2.12. A UE movements from RRC IDLE state to RRC CONNECTED nation whilst an RRC connection is successfully hooked up. A UE can pass back from RRC CONNECTED to RRC IDLE kingdom by liberating the RRC connection. In the RRC IDLE state, UE can acquire broadcast/multicast facts, monitors a paging channel to locate incoming calls, performs neighbor cell measurements and cellular selection/reselection and acquires machine facts. Furthermore, in the RRC IDLE state, a UE particular DRX (discontinuous reception) cycle can be configured by using higher layers to permit UE strength savings. Also, mobility is managed via the UE in the RRC IDLE
State.

In the RRC CONNECTED nation, the switch of uncast facts to/from UE, and the switch of broadcast or multicast statistics to UE can take location. At lower layers, the UE can be configured with a UE precise DRX/DTX (discontinuous transmission). Furthermore, UE video display units manage channels related to the shared facts channel to determine if facts is scheduled for it, offers channel nice comments facts, plays neighbor cell measurements and dimension reporting and acquires system records. Unlike the RRC IDLE kingdom, the mobility is managed by using the community on this kingdom.

Figure eleven Uplink logical, transport and bodily channels mapping.

Figure 12: UE states and country transitions.

6. SEAMLESS MOBILITY SUPPORT

An essential characteristic of a cellular wireless machine including LTE is aid for seamless mobility throughout eNBs and throughout MME/GWs. Fast and seamless handovers (HO) is specifically vital for postpone-touchy services which include VoIP. The handovers occur extra frequently across eNBs than across middle networks due to the fact the place protected by way of MME/GW serving a large range of eNBs is typically a great deal large than the vicinity covered through a unmarried eNB. The
signaling on X2 interface among eNBs is used for handover coaching. The S-GW acts as anchor for inter-eNB handovers.

In the LTE device, the network is based on the UE to locate the neighboring cells for handovers and therefore no neighbor cell information is signaled from the community. For the search and size of inter-frequency neighboring cells, best the service frequencies want to be indicated. An example of energetic handover in an RRC CONNECTED kingdom is shown in Figure 13 where a UE actions from the insurance vicinity of the supply eNB (eNB1) to the coverage vicinity of the goal eNB (eNB2). The handovers within the RRC CONNECTED country are community managed and assisted with the aid of the UE. The UE sends a radio measurement report to the supply eNB1 indicating that the sign high-quality on eNB2 is better than the sign excellent on eNB1. Shed Fabrication Services in Dasna As preparation for handover, the supply eNB1 sends the coupling information and the UE context to the target eNB2 (HO request) [6] on the X2 interface. The target eNB2 may additionally carry out admission control depending on the obtained EPS bearer QoS data. The target eNB configures the required sources in line with the received EPS bearer QoS facts and reserves a C-RNTI (cell radio network brief identifier) and optionally a RACH preamble.

Figure thirteen: Active handovers.

The C-RNTI presents a unique UE identification at the cell degree figuring out the RRC connection. When eNB2 signals to eNB1 that it is ready to carry out the handover via HO reaction message, eNB1 instructions the UE (HO command) to exchange the radio bearer to eNB2. The UE receives the HO command with the important parameters (i.E. New C-RNTI, optionally dedicated RACH preamble, feasible expiry time of the committed RACH preamble, and so on.) and is commanded via the source eNB to carry out the HO. The UE does no longer need to postpone the handover execution for delivering the HARQ/ARQ responses to supply eNB.

After receiving the HO command, the UE plays synchronization to the target eNB and accesses the target cell via the random get entry to channel (RACH) following a contention-unfastened process if a dedicated RACH preamble was allocated inside the HO command or following a rivalry-based process if no committed preamble was allocated. The network responds with uplink useful resource allocation and timing enhance to be implemented through the UE. When the UE has effectively accessed the target mobile, the UE sends the HO confirm message (C-RNTI) along with an uplink buffer reputation document indicating that the handover method is completed for the UE. After receiving the HO verify message, the target eNB sends a route transfer message to the MME to tell that the UE has modified cell. The MME sends a consumer plane replace message to the S-GW. The S-GW switches the downlink data direction to the goal eNB and sends one or extra "give up marker" packets on the vintage path to the source eNB after which releases any consumer-aircraft/TNL sources in the direction of the source eNB.

Then S-GW sends a person plane replace reaction message to the MME. Then the MME confirms the path transfer message from the goal eNB with the direction switch response message. After the route switch reaction message is received from the MME, the target eNB informs achievement of HO to the source eNB with the aid of sending release resource message to the supply eNB and triggers the release of sources. On receiving the release useful resource message, the source eNB can launch radio and C-plane related resources associated with the UE context.

During handover instruction U-plane tunnels may be mounted among the source ENB and the goal eNB. There is one tunnel established for uplink statistics forwarding and every other one for downlink information forwarding for each EPS bearer for which statistics forwarding is carried out. During handover execution, consumer facts can be forwarded from the supply eNB to the goal eNB. Forwarding of downlink consumer statistics from the supply to the target eNB ought to take location so as as long as packets are acquired on the supply eNB or the source eNB buffer is exhausted.

For mobility control within the RRC IDLE nation, idea of monitoring place (TA) is delivered. A tracking region usually covers a couple of eNBs as depicted in Figure 2.14. The monitoring area identity (TAI) statistics indicating which TA an eNB belongs to is broadcast as a part of device records. A UE can hit upon change of tracking vicinity whilst it receives a unique TAI than in its current mobile. The UE updates the MME with its new TA statistics as it moves throughout TAs. When P-GW gets data for a UE, it buffers the packets and queries the MME for the UE's location. Then the MME will web page the UE in its most present day TA. A UE may be registered in a couple of TAs simultaneously. This enables strength saving at the UE under situations of excessive mobility as it does no longer want to constantly update its vicinity with the MME. This characteristic additionally minimizes load on TA limitations.

8. MULTICAST BROADCAST SYSTEM ARCHITECTURE

In the LTE system, the MBMS either use a unmarried-cellular transmission or a multi-cellular transmission. In unmarried-mobile transmission, MBMS is transmitted simplest inside the coverage of a specific cell and therefore combining MBMS transmission from a couple of cells isn't always supported. The single-mobile MBMS transmission is accomplished on DL-SCH and for this reason makes use of the identical community structure because the unicast traffic.

Figure 14: Tracking location replace for UE in RRC IDLE country.

The MTCH and MCCH are mapped on DL-SCH for point-to-multipoint transmission and scheduling is executed with the aid of the eNB. The UEs may be allotted dedicated uplink feedback channels same to those utilized in unicast transmission, which allows HARQ ACK/NACK and CQI remarks. The HARQ retransmissions are made the usage of a collection (service unique) RNTI (radio community brief identifier) in a time body this is co-ordinated with the unique MTCH transmission. All UEs receiving MBMS are capable of acquire the retransmissions and combine with the original transmissions on the HARQ level. The UEs which can be allocated a committed uplink comments channel are in RRC CONNECTED state. In order to keep away from pointless MBMS transmission on MTCH in a cell wherein there may be no MBMS person, community can detect presence of customers inquisitive about the MBMS carrier by polling or via UE service request.

The multi-cellular transmission for the advanced multimedia broadcast multicast service (MBMS) is found out by means of transmitting equal waveform on the equal time from a couple of cells. In this case, MTCH and MCCH are mapped directly to MCH for point-to-multipoint transmission. This multi-cell transmission mode is called multicast broadcast unmarried frequency network (eMBSFN) as described in element in Chapter 17. An MBSFN transmission from a couple of cells inside an MBSFN vicinity is seen as a unmarried transmission by the UE. An MBSFN place accommodates a group of cells within an MBSFN synchronization place of a community that are co-ordinate to achieve MBSFN transmission. An MBSFN synchronization region is described as a place of the network wherein all eNBs can be synchronized and perform MBSFN transmission. An MBMS service place may encompass a couple of MBSFN areas. A cellular within an MBSFN synchronization vicinity may also shape part of a couple of SFN regions each characterized through one-of-a-kind content material and set of collaborating cells.

Figure 15. The eMBMS provider region and MBSFN areas.

An instance of MBMS carrier region inclusive of MBSFN regions, location A and location B, is depicted in Figure 2.15. The MBSFNA place includes cells A1-A5, mobile AB1 and AB2. The MBSFN location consists of cells B1-B5, cell AB1 and AB2. The cells AB1 and AB2 are a part of each MBSFN region A and location B. The cellular B5 is part of area B however does not make a contribution to MBSFN transmission. Such a mobile is referred to as MBSFN location reserved cell. The MBSFN region reserved cell may be allowed to transmit for different offerings at the resources allocated for the MBSFN however at a restrained strength. The MBSFN synchronization area, the MBSFN region and reserved cells can be semi-statically configured by O&M.

The MBMS structure for multi-cell transmission is depicted in Figure 2.16. The multicell multicast coordination entity (MCE) is a logical entity, this means that it may additionally be a part of every other network element which include eNB. The MCE plays capabilities consisting of the allocation of the radio sources used by all eNBs in the MBSFN vicinity in addition to figuring out the radio configuration inclusive of the modulation and coding scheme. The MBMS GW is likewise a logical entity whose major function is sending/broadcasting MBMS packets with the SYNC protocol to every eNB transmitting the carrier. The MBMS GW hosts the PDCP layer of the person plane and uses IP multicast for forwarding MBMS person statistics to eNBs.

The eNBs are connected to eMBMS GW through a natural consumer aircraft interface M1. As M1 is a pure person plane interface, no manipulate aircraft utility element is described for this interface. Two control plane interfaces M2 and M3 are described. The application part on M2 interface conveys radio configuration statistics for the multi-cell transmission mode eNBs. The utility component on M3 interface among MBMS GW and MCE plays MBMS consultation manage signaling on EPS bearer stage that includes strategies including consultation start and stop.

An crucial requirement for multi-mobile MBMS provider transmission is MBMS content material synchronization to enable MBSFN operation. The eMBMS person plane architecture for content synchronization is depicted in Figure 2.17. A SYNC protocol layer is described on the delivery community layer (TNL) to support the content material synchronization mechanism. The SYNC protocol carries additional statistics that permits eNBs to discover the timing for radio body transmission as well as come across packet loss.

Figure sixteen: eMBMS logical structure.

Figure 17: The eMBMS person aircraft architecture for content material synchronization.

The eNBs participating in multicell MBMS transmission are required to comply with content synchronization mechanism. An eNB transmitting simplest in single-cell carrier isn't always required to conform with the stringent timing necessities indicated via SYNC protocol. In case PDCP is used for header compression, it's miles located in eMBMS GW. The UEs receiving MTCH transmissions and taking part in at the least one MBMS feedback scheme want to be in an RRC CONNECTED country. On the alternative hand, UEs receiving MTCH transmissions without taking element in an MBMS comments mechanism can be in both an RRC IDLE or an RRC CONNECTED country. For receiving single-cellular transmission of MTCH, a UE may want to be in RRC CONNECTED state. The signaling by way of which a UE is precipitated to move to RRC CONNECTED nation entirely for unmarried-cellular reception functions is carried on MCCH.

8. SUMMARY
The LTE system is based on noticeably simplified community structure with simplest two varieties of nodes specifically eNode-B and MME/GW. Fundamentally, it's miles a flattened architecture that enables simplified network design while still helping seamless mobility and advanced QoS mechanisms. This is a first-rate change relative to traditional wireless networks with many more network nodes the usage of hierarchical network structure. The simplification of community become
in part feasible due to the fact LTE machine does now not aid macro-variety or smooth-handoff and as a result does no longer require a RNC in the get entry to community for macro-variety combining. Many of the opposite RNC features are integrated into the eNB. The QoS logical connections are provided among the UE and the gateway allowing differentiation of IP flows and meeting the requirements for low-latency programs.

A separate structure optimized for multi-mobile multicast and broadcast is supplied, which consists of two logical nodes particularly the multicast co-ordination entity (MCE) and the MBMS gateway. The MCE allocates radio assets in addition to determines the radio configuration to be used by all eNBs in the MBSFN region. The MBMS gateway broadcasts MBMS packets with the SYNC protocol to every eNB transmitting the provider. The MBMS gateway uses IP multicast for forwarding MBMS user information to eNBs. The layer 2 and radio useful resource manage protocols are designed to permit dependable delivery of records, ciphering, header compression and UE strength financial savings.