All You Need to Know about LTE Architecture

The rapid development of numerous communication technologies, both fixed and mobile, has resulted in a growing demand for Internet access. The Internet's enormous influence in today's world of information transmission is evident. Quality communication enables individuals to work, study, communicate, and access streaming movies, audio, and internet services with a variety of commercial firms and government organisations more effectively.

Standard LTE network allows carriers and operators to deliver high-speed connectivity for mobile phones and data terminals while also optimising current networks for additional vertical market applications like transportation and smart grid. With growing applications like gaming, social networking, and video on mobile devices, the use of mobile broadband services is accelerating at an unprecedented rate. 4G, namely LTE technology, allows customers to bring the exact same user experience they enjoy at home or at work with them when they are on the road.

LTE: What Exactly Is It?

LTE, the acronym for Long-Term Evolution, is basically a 4G (fourth-generation) wireless standard that improves speed and network capacity and several other cellular devices over 3G (third-generation) technology.

LTE provides faster peak data transfer rates than 3G, with initial speeds of up to 100 Mbps downstream and 30 Mbps upstream. It has lower latency, backward compatibility with existing UMTS and GSM technologies, and expandable bandwidth capacity. Following the development of LTE-A (LTE-Advanced), peak throughput on the order of 300 Mbps was achieved.

"Long-Term Evolution": Why Is LTE Called So?

LTE was not initially classified as real 4G. The ITU (International Telecommunication Union) first described 4G as a cellular standard with the potential to transfer data at a speed of 1 Gbps for a stationary user and 100 Mbps for a mobile user. The ITU modified their stance in December 2010, applying 4G to LTE and numerous other wireless protocols.

LTE Network Architecture: Everything You Need to Know

The following network components are included in the basic LTE architecture:

• LTE Evolved Universal Terrestrial Radio (LTE EUTRAN)
• LTE Evolved Packet Core (LTE EPC)

LTE EUTRAN

It's a radio access network standard designed to replace HSDPA, HSUPA and UMTS. In contrast to HSPA, the E-UTRA of the LTE air interface mechanism is totally new. It has faster data speeds, reduced latency, and is designed for packet data. Evolved Universal Terrestrial Radio (EUTRAN) is made up of eNBs (electronic nodes). EUTRAN is in charge of all radio management in LTE. 

When the UE is turned on, the eNB is in charge of Radio Resource Management, which includes radio admission control, radio bearer management, allocating downlink and uplink to the UE, and so on. When a UE packet arrives at the eNB, the eNB must compress the IP header and encrypt the data stream. It's also in charge of appending a GTP-U header to the payload and transmitting it to the SGW.

The control plane must be created before data can be transferred. eNB is in charge of selecting an MME utilising the MME selection mechanism. Because the eNB is the sole entity on the radio, it is responsible for QoS. Other functions include broadcast message transmission, paging message scheduling and transmission, as well as bearer-level rate enforcement, which is also performed by eNB.

LTE EPC (Evolved Packet Core)

The LTE network architecture of the EPC (Evolved Packet Core) comprises of

• PGW
• SGW
• PCRF
• HSS

PGW (PDN Gateway)

Well, PGW closes the SGi interface to the PDN. It's in charge of every IP packet-based function like UE IP address assignment, deep packet inspection, transport level packet marketing in downlink and uplink, accounting, and so on. PGW calls PCRF in order to assess the quality of service for bearers. It's also in charge of DL and UL rate enforcement.

SGW (Serving Gateway)

The interface to EUTRAN is terminated by the serving gateway. Each UE has a single Serving GW connected with EPS at any moment. For inter-eNB handovers, SGW functions as a local mobility entity. It also serves as a mobility anchor for 3GPP interoperability. SGW is in charge of packet routing and forwarding and buffering downlink packets. SGW is in charge of downlink packet marking, whereas eNB is in charge of uplink packet marking.

PCRF (Policy Control and Charging Rules Function)

The Policy Control and Charging Rules Function (PCRF) is in charge of policy control decision-making together with regulating the flow-based charging features in the P-Policy GW's Control Enforcement Function (PCEF). The PCRF offers QoS authorisation (QoS class identification [QCI] and bit rates) that determines how a certain data flow will be processed in the PCEF and guarantees that it is consistent with the user's subscription profile.

HSS (Home Subscriber Server)

The Home Subscriber Server (HSS) is basically a central database that stores subscription and user data. The HSS service includes call and session setup assistance, mobility management, access authorisation, and user authentication. Also, it contains data regarding PDNs that the user may connect to. Furthermore, the HSS stores dynamic data such as the identification of the MME to which the user is presently linked or registered. The Home Subscriber Server may additionally include an AUC (authentication centre), which creates security keys and authentication vectors.

LTE Architecture: Advantages and Disadvantages

LTE delivers considerable performance increases over previous generations as the fastest and most widely available cellular telecommunications network. Here are a few of the advantages of LTE network architecture:

• Rapid Download Speeds: 4G download rates can exceed 100 Mbps, allowing you speedier access to information and online services. According to one survey, 67 per cent of firms utilising LTE in the United States have witnessed productivity benefits, while 47 per cent have been able to save expenditures.
• Quicker Web Browsing: We can move big volumes of data between customers thanks to faster download and upload rates. As previously said, 4G LTE lowers latency, allowing data to transfer quickly from one place in a network to another. That implies it will take less time to load webpages, backup data to the cloud, and view files remotely.
• Longer Battery Life: Reduced latency implies quicker data transfers and reduced battery use. Users may improve the lives of their smartphone batteries by utilising LTE. 4G LTE consumes more power than previous generations, but it transmits data so swiftly that it may accomplish a task faster.
• High-Quality Live and Video Streaming: We have increasingly relied on the video to stay connected online, from video conferencing to streaming services. Many organisations with remote locations monitor these sites using real-time 4G video streams, typically monitoring many locations from a single office.
• Decreased Network Loads: Since LTE sends significant volumes of data between users, network consumption appears to be increasing. However, the quicker transmission speed and lower latency mean that data travels swiftly, minimising network burden. This leads to fewer service crashes, which can be critical for enterprises that must remain connected to the cloud, such as those with many distant locations.

Despite these major advantages, LTE has certain drawbacks. Here are some things to think about when putting LTE in place.

• Can't Be Used with Older Mobile Phones: Unluckily, if your phone isn't already compatible with 4G LTE, you won't be able to connect it to an LTE network. However, LTE is very adaptable and interoperable with the majority of existing mobile networks. As 3G becomes less popular as a telecommunications option, more businesses are upgrading to 4G LTE for a quicker, more dependable connection.
• Not Available Everywhere: As a new technology, 4G LTE networks are not yet the norm for cellular telecommunications firms. More cellular service providers must enhance their network infrastructure in order to give stronger signals, particularly while travelling on buses and trains.
• 4G LTE Devices Are Expensive: Since your older devices may not be compatible with 4G LTE, you may elect to replace all your gadgets with smartphones that include built-in LTE. These newest smart gadgets are particularly built to deliver the quickest internet connections and provide a robust 4G LTE connection.

The Key Takeaway

The LTE architecture of the 4G network has become the industry standard for mobile communications. Both the 1st and 2nd generation technologies were primarily focused on telephony, and 3G later transitioned to mobile data. Furthermore, 4G LTE enhanced mobile data communications by focusing primarily on this area to enable widespread mobile data access.

If you are interested in learning the intricacies of LTE architecture, Skill-Lync is a great option to learn about the LTE architecture of 4G networks.

Skill-Lync's network training courses will give you a complete grasp of the LTE system's architecture and how the entire system functions.