eNodeB (Evolved NODE B) - the radio of the LTE network

eNodeB (Evolved Node B), is the basestation of the LTE network.

His role in the LTE network is to provide radio connectivity for the UE (smartphone) to access the LTE core network (EPC) services – Internet.

Keep reading to learn all there is to know about the eNodeB!

To summarize the point, the eNodeB does:

  • Radio Resource Management, Radio Admission Control, Radio Bearer Control
  • Connection mobility control, dynamic allocation of resources Uplink and Downlink to UEs.
  • IP header compression and user data stream encryption
  • MME selection at LTE UE attachment
  • Transmission and scheduling of paging messages
  • Transmission and scheduling of broadcast information
  • Measurement reporting configuration for mobility and scheduling
Image showing how LTE SatSite, the yate-based eNodeB, connects by S1-AP and GTP to the LTE Core network and by X2 to other eNodeBs

To better understand the concept of eNodeB, you need to have a clear image of its functions and how it communicates to other elements of the LTE network.

The sections below describe the eNodeB architecture and the role of each component, as well as our evolved Node B solution equipment.

We provide two types of eNodeB solution:

Main functions of the LTE eNB

  • Radio resource management, which includes:
    » Radio Bearer Control –responsible for the setup, maintenance and the release of radio bearers and its resource configuration
    » Dynamic Resource Allocation, covering the release and allocation of radio resources in both the user plane and the control plane
  • MME selection, which includes:
    » Enabling the UE to be served by an MME while the UE is in the “attach” procedure
    » Enabling the UE to be served by a different MME while being in a network
    » The establishment of the route towards an MME, based on the information provided by the UE when the routing information is not available
  • Routing of user plane packets towards the S-GW
  • Packet compression and ciphering, which includes:
    » Encryption and decryption of packets through ciphering algorithms
    » Header compression for downlink packets and header decompression for uplink packets
  • Message scheduling and transmission, which includes:
    » The transmission of paging messages, OM messages or broadcast information via the Uu interface
    » The reception of broadcast information and paging messages from an MME and the OM messages from the operation and maintenance center

How the evolved Node B communicates to other elements of the network

The LTE eNB communicates with the UE, other eNodeBs, and the Evolved Packet Core (EPC). It uses various interfaces such as the Uu, X2, and S1.

  • LTE – Uu
    The radio interface that connects the UEs to the eNodeB and vice versa. It is in charge of handling all the signaling messages between the MME and the eNodeB. It is also responsible for handling the traffic between the UE and the S-GW.
  • X2
    Provides connectivity between two or more eNodeBs. It has two main parts:
    • The X2-C: this is the interface between the control planes of eNodeBs
    • The X2-U (GTP-U): this is the interface between the user planes of eNodeBs
  • S1
    Connects the E-UTRAN and the EPC for both the user planes and the control planes. It has two main parts:
    • The S1-AP: this belongs to the control plane
    • The S1-U (GTP-U): this belongs to the user plane
Image showing how LTE SatSite, the yate-based eNodeB, connects by S1-AP and GTP to the LTE Core network and by X2 to other eNodeBs

In order use a full production eNodeB you need a Spectrum License

Everyone who wants to buy an LTE eNB and use it for a Mobile Network or a private one needs to get a spectrum license.  The radio spectrum is the range of frequencies of electromagnetic radiation. It includes their respective wavelengths and photon energies.
To get a spectrum license, you need to take part in a spectrum auction. A spectrum auction is a process that a government uses to sell the rights to broadcast signals. They divide limited spectrum resources over specific bands of the electromagnetic spectrum.

There is also the “ lightly licensed” option. You can register for a spectrum license with a small fee, like CBRS in the US. Of course, different countries may have different views about their spectrum resources. It’s great to see more spectrum available to both operators and new entrants. There’s still a lack of clarity of which bands, modes, and options will be adopted outside the US.

Types of businesses that need an eNodeB

  • Mobile Operators
    A mobile network operator (MNO) is a provider of wireless communications services. They are also known as a wireless service provider, carrier, cellular company, or mobile network carrier. They own and control all the elements necessary to sell and deliver services to an end-user. It also includes radio spectrum allocation, wireless network infrastructure, backhaul infrastructure, billing, customer care, provisioning computer systems, and marketing.
  • Private mobile networks
    » A private LTE network is a solution for enterprises that aim to reproduce a high-speed 4G network. The user is trying to set up a small scale network in a particular location to achieve its business goals. Private LTE is competing with WiFi networks. LTE as a more reliable alternative to the WiFi networks. It has better coverage and real Quality of Service controls.
    » Private networks operate using different types of the spectrum: unlicensed, shared, and licensed. Each has different license terms and access restrictions.
    » Private cellular networks can operate using three different types of the spectrum — unlicensed, shared, and licensed — and each have different license terms and access restriction.
    » Types of private network applications - oil & gas platforms, mines, Warehouses & Manufacturing companies, governments, and departments of defense.

Yate-based eNodeB solutions

We provide two types of eNodeB solutions for operators and private networks. Our solution is highly scalable and suitable for any operator size and structure.

Full production LTE eNodeB

SatSite model 142 is a self-reliant macrocell eNodeB solution. It can be configured via software to operate as a 2.5G GSM/GPRS BTS+BSC. There is no need for a CPRI because our eNodeB solution can work with any Ethernet backhaul. Finally, SatSite 142 has the largest power output of 20 watts RMS for LTE or GSM operation.



  • Software configurable - 4G LTE or 2.5G GSM/GPRS.
  • Software upgradable to future LTE and LTE-A Releases.
  • Can be used with any IP backhaul
  • Local break-out of GPRS and LTE IP traffic for edge computing
  • Local media routing for GSM speech calls.
  • GSM backhaul loading as little as 8 kbit/sec/call.
  • Can be powered from solar panels in most parts of the world
  • Linux-based OS means lower management costs.


  • Reduced civil infrastructure costs
  • Reduced time-to-market
  • Reduced costs for operation and support
  • Interconnects with any LTE core
  • Network and existing LTE RAN
  • Lightweight ; SatSite eNodeB is a 31cmX20cmX10cm unit weighing 5Kg
  • Interoperability; supports S1-AP and GTP to connect to any LTE EPC

LTE LabKit - eNodeB for tests and research

The LTE LabKit is a Lab LTE ENB running on a small factor PC computer. It comes in a light package (5kg or 10 pounds, including the phones). It is intended for MNO laboratory use, IoT, and M2M application development. It is also used as a Callbox for IoT production lines, mobile phone vendors, and researchers.


  • Wireshark monitoring traffic inside BTS and EnodeB interfaces ( S1AP, GTP )
  • LTE enb working mode
    LTE EnodeB connected to a MME, MiniCore or HostedCore
    » LTE Release 12, FDD (Radio Interface)
    » LTE Release 12, TDD
  • Supports both IPv4 and IPv6 connection
  • GPRS with Local breakout
    MS receive data services using their LabKit internet connection
  • Four working modes:
    » GSM NiPC (Network in a PC)
    » GSM roaming
    » GSM dataroam
    » LTE eNodeB
  • Outbound connection through SIP/IAX in NiPC mode
  • Works both stand alone and with external components
  • Access to the Hoasted Core
    The Hosted Core is a free service that allows users to experiment with a fully-functional GSM/GPRS or LTE/IMS network.
LTE LabKit connected to Hosted Core acting as a full LTE and GSM network