Sign In
New Customer?

Defense

Technology Licensing

LTE System Solutions

The overall EPS network architecture, including the network elements and the standardized interfaces is comprised of the EPC and the access network E-UTRAN. While the EPC consists of many logical nodes, the access network is made up of essentially just one node, the evolved NodeB (eNodeB), which connects to the UEs. Each of these network elements is interconnected by means of interfaces that are standardized in order to allow multi-vendor interoperability.

The functional split between the EPC and E-UTRAN is shown.

LTE EPS Network Elements are:

  • UE
  • eNodeB
  • MME
  • S-GW
  • P-GW

LTE Protocol Architecture:

  • E-UTRAN
  • EPC

LTE UE

LTE UE is partitioned into following categories:

  • Radio,
  • Physical Layer (PHY)
  • Protocol Stack & Applications

SAI provides full end to end solution for UE PHY and Protocol Stack in combination with any third party radio. The solution complies fully with 3GPP LTE Release 8 and Release 9. SAI is also developing a complete compliant solution for LTE Advanced (Release 10 & beyond) with expected delivery in March, 2012.

UE PHY

UE PHY Highlights

  • OFDMA in DL and SC-FDMA in UL
  • Duplexing schemes; full/half duplex FDD, and TDD
  • Scalable channel bandwidth up to 20 MHz and higher bandwidths of 40 MHz to 100 MHz with LTE Advanced
  • MIMO processing with 2x2 UL and 4x4 DL antennas with layering and pre-coding options
  • Adaptive modulation and coding, QPSK, 16QAM, and 64QAM for DL. QPSK and 16QAM for UL
  • Two frame structures: Type-1 shared by both full- and half-duplex FDD, Type-2 applicable to TDD
  • Turbo code

UE PHY Functional Block Diagram

UE PHY Deliverables

  • Matlab IP source code
  • C/ DSP IP source code
  • DSP based implementation
  • FPGA based implementation Verilog/VHDL
  • Test Bench/Test Vector
  • Software reference design document
  • Protocol test tool code
  • Complete reference design kit
  • User manual

UE Protocol Stack

LTE Protocol Stack is implemented for User Equipment (UE) terminals compliant to the 3GPP Release 8 as well as Release 9 specifications. It consists of a fully optimized Layer 2, Layer 3 and NAS LTE protocol software enabling the highest uplink and downlink data rates. This module has been integrated & validated with IOT in multiple third party commercial processors and solutions.

The architecture is designed to be scalable and portable to different hardware platforms and operating systems with optimum processor utilization & low memory footprint. The LTE protocol stack is fully supported by a suite of advanced development, test and verification tools to enable rapid product development. SAI also provides dedicated support and customization services to assist with porting, integration and end-to-end LTE system verification from lab tests to field trials.

UE Protocol Stack Highlights

  • Conformance to 3GPP standards through integration and validation with different systems as well as inter-operability with various infrastructure vendors
  • Adaptable future-proof design to support continuously evolving standards towards LTE advanced (LTE Release 10 and beyond)
  • Supports maximum LTE data rates
  • Scalable and portable to integrate with different embedded hardware platforms and operating systems
  • Designed to meet optimum memory and performance requirements
  • Comprehensive set of debug trace and statistical logging tools supported
  • Supported OS are: Linux , Android, WinCE, VxWorks, Nucleus and can be customized to customer’s specific RTOS

LTE Layer- 2

Layer-2 software consists of the LTE MAC, RLC and PDCP protocol sub-layers. Key features are:

  • MAC – All LTE transport channels with optional MBMS
  • RLC – UM, TM, AM modes
  • PDCP – Ciphering, integrity protection and ROHC v1 and upgraded ROHC v2

LTE Layer- 3

The LTE Layer 3 software comprises of the Radio Resource Control (RRC) protocol. The LTE RRC layer provides broadcast of system information; configures the RLC, MAC and PDCP layers; carries out mobility functions and QoS management functions. Key features are:

  • System information handling
  • Paging
  • Measurements and cell reselection
  • Handover
  • RRC security and integrity

LTE Non Access Stratum ( NAS )

The LTE NAS protocol software enables communication with the MME in the LTE core network and handles functions of mobility management and session management. Key features are

  • Security
  • LTE SIM
  • AT command handling
  • Call control
  • Mobility management

UE Protocol Stack Deliverables

  • Binary or ANSI C source code for core protocol components
  • OS abstraction layer for target RTOS/platform
  • Fully documented APIs with user manuals
  • Continuous update of functionality based on the latest 3GPP LTE Standards (towards LTE Advanced , Release 10 and beyond)
  • Product customization support for both remote and on-site
  • Complete solution in reference platform

LTE ENodeB

LTE ENodeB is partitioned into following categories

  • Radio
  • Physical Layer (PHY)
  • Protocol Stack & Applications
  • Customizable Digital Frontend

SAI provides full end to end solution for eNodeB PHY and Protocol Stack in combination with any third party radio. The solution complies fully with 3GPP LTE Release 8 and Release 9. SAI is also developing a complete compliant solution for LTE Advanced (Release 10 & beyond) available by March, 2012.

ENode PHY

ENode PHY Highlights

  • OFDMA in DL and SC-FDMA in UL
  • Duplexing schemes; full/half duplex FDD, and TDD
  • Scalable channel bandwidth up to 20 MHz and higher bandwidths of 40 MHz to 100 MHz with LTE Advanced
  • MIMO processing with 2x2 UL and 4x4 DL antennas with layering and pre-coding options & higher MIMO configurations up to 8x8 in LTE Advanced
  • Adaptive modulation and coding, QPSK, 16QAM, and 64QAM for DL
  • Two frame structures: Type-1 shared by both full- and half-duplex FDD, Type-2 applicable to TDD Turbo code

ENode PHY Functional Block Diagram

ENode PHY Deliverables

  • Matlab IP source code
  • C/ DSP IP source code
  • DSP based implementation
  • FPGA based implementation Verilog/VHDL
  • Test Bench/Test Vector
  • Software reference design document
  • Protocol test tool code
  • Complete reference design kit
  • User manual

ENode Protocol Stack

  • Conformance to 3GPP standards through integration and validation with different systems as well as inter-operability with leading infrastructure vendors
  • Adaptable future-proof design to support continuously evolving standards towards LTE-Advanced (LTE Release 10 and beyond)
  • Supports highest UE category (maximum LTE data rates)
  • Scalable and portable to integrate with different embedded hardware platforms and operating systems
  • Designed to meet optimum memory and performance requirements
  • Comprehensive set of debug trace and statistical logging tools supported
  • Supported OS are: Linux , Android, WinCE, VxWorks, Nucleus and also can be customized to customer’s specific RTOS                    

LTE Layer 2

Layer-2 software consists of the comprehensive implementation of the LTE MAC, RLC and PDCP protocol sub-layers. Key features are:

  • MAC – All LTE transport channels with optional MBMS
  • RLC – UM, TM, AM modes
  • PDCP – Ciphering, integrity protection and ROHC v1 and upgraded ROHC v2

LTE Layer 3

The LTE Layer 3 software comprises of the Radio Resource Control (RRC) protocol. The LTE RRC layer provides broadcast of system information; configures the RLC, MAC and PDCP layers; carries out mobility functions and QoS management functions. Key features are:

  • System information handling
  • Paging
  • Measurements and cell reselection
  • Handover
  • RRC security and integrity

Radio Resource Management (RRM)

Radio resource management (RRM) – This covers all functions related to the radio bearers, such as radio bearer control, radio admission control, radio mobility control, scheduling and dynamic allocation of resources to UEs in both uplink and downlink.

EnodeB Protocol Stack Deliverables

  • Binary or ANSI C source code for core protocol components
  • OS abstraction layer for target RTOS/platform
  • Fully documented APIs with user manuals
  • Continuous update of functionality based on the latest 3GPP LTE Standards
  • Product customization support services for both remote and on-site
  • Full solution on reference platforms based on PowerPC, MIPS, Arm and x86.

LTE EPC

LTE EPS (LTE / SAE ) Architecture

The EPS architecture is made up of an EPC (Packet Core Network) and eUTRAN Radio Access Network.

EPC Key Network Elements

The core network (Evolved Packet Core in SAE) is responsible for the overall control of the UE and establishment of the bearers. The main logical nodes of the EPC are:

  • Mobility Management Entity (MME)
  • Serving Gateway (S-GW)
  • PDN Gateway (P-GW)

Mobility Management Entity ( MME )

This is a key control plane element. Among other functions, it is in charge of managing security functions (authentication, authorization, NAS signaling), handling idle state mobility, roaming, and handovers. Also selecting the Serving Gateway (S-GW) and Packet Data Network Gateway (PDN-GW) nodes is part of its tasks. The S1-MME interface connects the EPC with the eNodeBs.

Serving Gateway ( S – GW)

The EPC terminates at this node, and it is connected to the E-UTRAN via the S1-U interface. Each UE is associated to a unique S-GW, which will be hosting several functions. It is the mobility anchor point for both local inter-eNodeB handover and inter 3GPP mobility. S-GW performs inter-operator charging as well as packet routing and forwarding.

PDN Gateway ( P – GW)

This node provides the UE with access to a Packet Data Network (PDN) by assigning an IP address from the PDN to the UE, among other functions. Additionally, the evolved Packet Data Gateway (ePDG) provides security connection between UEs connected from an untrusted non-3GPP access network with the EPC by using IPSec tunnels.

SAI has developed MME, S-GW, P-GW which are fully compliant with 3GPP Release 8 and 9.0. SAI is working towards LTE Advanced (Release 10 and beyond).

With licensing UE or eNodeB software, SAI provides EPC software running on Intel Servers. These modules are validated with rigorous interoperability tests with other vendors.

LTE Advanced

What’s new in LTE Advanced

In the feasibility study for LTE-Advanced, 3GPP determined that LTE-Advanced would meet the ITU-R requirements for 4G. The results of the study are published in 3GPP Technical Report (TR) 36.912. Further, it was determined that 3GPP Release 8, 9, and 10 LTE could meet most of the 4G requirements apart from uplink spectral efficiency and the peak data rates. These higher requirements are addressed with the addition of the following LTE-Advanced features.

  • Wider bandwidths, enabled by carrier aggregation
  • Higher efficiency, enabled by enhanced uplink multiple access and enhanced multiple antenna transmission (advanced MIMO techniques)
  • Coordinated multipoint transmission and reception (CoMP)
  • Relaying
  • Support for heterogeneous networks
  • LTE self-optimizing network (SON) enhancements
  • Home enhanced-node-B (HeNB) mobility enhancements
  • Fixed wireless customer premises equipment (CPE) RF requirements

System Performance Requirements 

             Spectrum Flexibility

In addition to the bands currently defined for LTE Release 8, TR 36.913 identifies the following new bands:

  • 450–470 MHz band
  • 698–862 MHz band
  • 790–862 MHz band
  • 2.3–2.4 GHz band
  • 3.4–4.2 GHz band
  • 4.4–4.99 GHz band

Some of these bands are now formally included in the 3GPP Release 9 and Release 10 specifications. Note that frequency bands are considered release independent features, which means that it is acceptable to deploy an earlier release product in a band not defined until a later release.

LTE Advanced is designed to operate in spectrum allocations of different sizes, including allocations wider than the 20 MHz in Release 8, in order to achieve higher performance and target data rates. Although it is desirable to have bandwidths greater than 20 MHz deployed in adjacent spectrum, the limited availability of spectrum means that aggregation from different bands is necessary to meet the higher bandwidth requirements. This option has been allowed for in the IMT-Advanced specifications.

SAI LTE – Advanced Development

SAI is heavily invested in developing complete LTE solution for 3GPP LTE Release 10 and beyond (LTE Advanced). The areas of enhancements are based on current solutions described in LTE UE and eNodeB. The EPC cores are being upgraded to support full system validation based on solutions described in LTE EPC page.

Following are snapshot of developments

LTE UE

  • LTE PHY
  • LTE Protocol Stack
  • Complete Reference Platform

LTE ENodeB

  • LTE PHY
  • LTE Protocol Stack
  • Complete Reference Platform

LTE EPC

  • MME
  • S-GW
  • P-GW

A few key design enhancements in 802.11ac compared to 802.11n are

1) Wider channel width i.e. 80 MHz mandatory, or 160 MHz optional (40 MHz maximum in IEEE 802.11n)

2) Higher modulation i.e., 256 QAM (64 QAM in case of IEEE 802.11n)

3) MU-MIMO (Multi User MIMO, SU-MIMO in case of 802.11n).

4) Short GI which is 400 μsec

5) STBC (Space Time Block Coding) and LDPC (Low Density Parity Check) codes

6) Maximum up to eight spatial streams (four in IEEE 802.11n)

7) The SAI 802.11ac PHY includes support for these features:

- Support for all channel combinations including 160 MHz contiguous as well as 80+80 MHz combination

- Full PLCP header support for VHT mode including VHT-SIG-A/B as well as VHT-LTF and VHT-STF 

- PHY configuration and legacy protection in mixed mode

– including CTS/RTS and L-SIG-TXOP - All MCS and FEC modes defined by the standard

- Multiple antenna support in a number of modes including

8) NxM MIMO combinations (Up to 8x8) with no restrictions on N and M

9) Spatial mapping and STBC support

10) All CSD combinations

11) SU and MU MIMO             

- Receiver supports includes channel estimation and MIMO detection             

- Beamforming support includes

12) Steering vector calculations using antenna measurements

13) Implicit/Explicit beam forming reports

14) VHT compressed beamforming report

15) MU-MIMO beamforming report

16) MIMO beamforming algorithms using received reports - Performance data for this is measured

17) Using channel definitions from the 802.11ac standard (in draft form) models a-f

18) Delivering performance data such a BER/PER as well as RSSI and Channel frequency response per link.

19) SAI can license 802.11ac Phy & Mac as a complete solution.