eNodeB

What is eNodeB?

The eNodeB, or evolved NodeB, is a critical component of the Long Term Evolution (LTE) network architecture. It functions as the base station for LTE cellular networks. In addition, it serves as a high-speed data switch that interfaces with User Equipment (UE) devices and the core network infrastructure.

The key functions of this component include radio resource management, radio frequency signal processing, packet processing, mobility management, authentication, and security.

Sophisticated algorithms and protocols, such as Orthogonal Frequency Division Multiple Access (OFDMA) and Multiple Input Multiple Output (MIMO) technology enable the eNodeB to dynamically allocate radio resources and ensure the efficient and secure transmission of data across the network.

Specifications

Nybsys eNodeBs at the edge of the network follow the latest 3gpp specifications and are implemented using a versatile software framework, that has been at the forefront of many business-critical LTE deployments around the world. The system is built using COTS hardware but modified with our own BMC which protects from unwanted access by malicious actors. The system is open so that it can be inspected and modified if required. Our eNodeBs are designed and tested to operate in high humidity and high-temperature conditions. A high-level overview of our eNodeBs follows.

Physical Layers of our eNodeB

LTE protocol stack functions consist of Medium Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), and Radio Resource Control (RRC). LTE is the latest generation of the 3GPP standards. The LTE standard specifies an IP-only network supporting data rates up to 150 Mbps. These high data rates will enables new applications and services such as voice over IP, streaming multimedia, videoconferencing or even a high-speed cellular modem. The following are the supported specification in our proposed LTE eNodeB.

LTE release 14 compliant
FDD and TDD configurations
Supported bandwidths: 1.4, 3, 5, 10, 15 and 20 MHz
Handle several cells in intra-band or inter-band configurations
Transmission modes: 1 (single antenna) and 2 to 10 (MIMO 4×4)
Wideband CQI/PMI reports
HARQ support
Timing measurement thru the PRACH
Closed-loop UE power control
Frequency based MMSE equalizer
Highly optimized software turbo decoder

PAPR reduction support
Support of other radio heads can be added with an external shared library.
Positioning Reference Signals (PRS) support
CSI-RS support
Multi-cluster PUSCH allocation
PUCCH 3 and PUCCH channel selection support
Carrier Aggregation support with cross carrier scheduling (tested with 3 DL channels, supports up to 5 DL channels)
CoMP testing features (DMRS scrambling identity and QCL parameters can be selected)
256QAM DL support for PDSCH and MBMS
Support of release 11 TDD special subframe configurations 7 and 9

Protocol Layer of Evolved Node B (eNodeB)

LTE protocol stack functions consist of the Medium Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), and Radio Resource Control (RRC). LTE is the latest generation of the 3GPP standards. The LTE standard specifies an IP-only network supporting data rates up to 150 Mbps. These high data rates will enables new applications and services such as voice over IP, streaming multimedia, videoconferencing or even a high-speed cellular modem. The following are the supported specification in our proposed LTE eNodeB.

LTE release 14 compliant
Implements the MAC, RLC, PDCP and RRC layers
Proportionally fair MAC scheduler with QoS support
Support of full and half duplex UEs
DRX support
Number of active users only limited by the available bandwidth.
Fully configurable System Information Blocks
Integrity check and encryption using the AES, Snow3G and ZUC algorithms

Support of RRC measurement with measurement gap
Supports intra eNodeB, S1 or X2 handovers
QoS support with user selectable DRB configuration for each QCI
ROHC support (RTP, UDP and IP v1 profiles)
Public Warning System (CMAS/ETWS) support
MBMS support
Category 0 UE support
eDRX support

LTE M

Long Term Evolution for Machines: LTE-M. It specifically refers to LTE CatM1, suitable for the IoT. LTE-M is a low power wide area technology which supports IoT through lower device complexity and provides extended coverage, while allowing the reuse of the LTE installed base. LTE M is popular for connecting sensors for military deployments for example helmet sensors can directly interact with the centralized command and control system using LTE M technologies. Following are the supported features for LTE M:

Release 14 compliant
Category M1 UE support
TM6 and TM9 support
FDD only (FDD and HD-FDD UEs are supported)
Support of multiple CE levels (only CE-Mode A is supported)

Support of message repetition for MPDCCH, PDSCH and PUSCH in full duplex. No message repetition for PUCCH and PRACH
Support of localized MPDCCH transmission
EPDCCH support for Category M1
No frequency hopping
Bandwidth must be >= 5 MHz

NB-IOT

Narrowband IoT (NB-IoT) is a Low Power Wide Area Network (LPWAN) radio technology standard developed by 3GPP to enable a wide range of cellular devices and services. The specification was frozen in 3GPP Release 13 (LTE Advanced Pro), in June 2016. The following are the supported features of NB-IOT in our eNodeB infrastructure components.

NB-IoT release 14 compliant
Single-tone and multi-tone category NB1 and NB2 UE support
15 kHz and 3.75 kHz subcarrier spacing are supported
All operation modes (in-band, guard band and standalone) are supported
Multiple NB-IoT and LTE cells can be used at the same time in the same eNodeB

Support of multiple coverage levels
Support of all NPDCCH, NPDSCH, NPUSCH and NPRACH configurations
Support of control plane CIoT optimization
Support of multi-DRB mode

eNodeB Radio Interface

Proposed eNodeB is a software platform installed in COTS hardware which can be virtualized and can operate as virtual RAN. The following radio interfaces will be supported by the proposed eNodeB:

C radio API to integrate any radio device
Compatible with various SDR platform and high power RRH

eNodeB Network Interface

The software based eNodeB needs to support different network interfaces. Most of the interfaces are connected by using different VLAN or segment in the IP networks. The following interfaces are supported by proposed eNodeB:

Standard S1AP and GTP-U interfaces to the Core Network. Several PLMNs and S1 interfaces can be used simultaneously.
X2AP interface between eNodeBs
M1 and M2 interfaces for MBMS
IPv6 support

eNodeB User Interface

Configurable logging system for all channels with built-in text decoders
Wireshark MAC-LTE capture
Plots for QAM constellations and channel response
Remote API using WebSocket
Command line monitor
Test commands to initiate handover and to dynamically change the power level of each cell