General explanation in Telecommunication Services

The telecommunication service in the world had experienced a great leap within a past few decade. In the world, there are 6 billion people own a mobile phones. So, the main purpose of the post is to provide a general explanation about 1G, 2G, 3G and 4G for those who are still unaware and blur with the latest technology in the telecommunication system.

In the communication system the "G" in 1G, 2G,3G and 4G stands for "generation". 1G is the first and oldest methodology to provide link between each user in the network. In 1G, it is a technology which is using narrow band analogue wireless network. With limited bandwidth, the network only able to provide voice calls and capable for sending text messages. Besides that, a limited service range and expensive cost which may be faced by 1G users. Thus, 2G had been developed and quickly replaced 1G in order to satisfy the requirement of the market. In 2G wireless cellular mobile services which has the similar voice calls as 1G, but a main feature different from 1G is that the facility of short message service (SMS) is provided. In order to transmit text data, 2G GSM network service range from 800MHz/900MHz or 1800/1900 spectrum while the bandwidth is 30-200kHz. The another difference between 1G and 2G is that, 2G owns a semi-global roaming facility while 1G only able to work within in the premises of the particular nation.

To further improve the current network, 2.5 and 3G appeared. 2.5G is the intermediate methodology which was introduced mainly for involving latest bandwidth technology with addition to the existing 2G. Thus it had been replaced by 3G very soon. It is because 2.5G also facing the similar problem as 2G that is limitation of bandwidth thus limiting the data speed. In 3G wide band wireless network, it is so called wide band because 3G operates at a range of 2100MHz and has a bandwidth of 15MHz-20Mhz, thus with the help of 3G, we can access many new services, global roaming, giving clarity of voice as well can talk without any disturbance, fast communication, internet, mobile TV, video call, MMS, streaming and etc.

In 3G, the data are sent through the technology call Packet Switching, it is actually done by supplying various addressed packets and will be interconnected to have the conversation. Thus, it is not necessary to create a interpreted through Circuit Switching. It is a highly sophisticated form of communication that has came up in the last decade. Since 3G is good enough but why 4G still is developed? It is because 4G able to promise a downloading speed of 100Mbps which is mush faster than in 3G. 

3G and 4G are good but why it is still not popular and implemented widely over the world? The main reasons is the cost. For fully using 3G and 4G features, users need to pay more, thus market in those developing countries will be smaller. Besides that, a wide band frequency spectrum for 3G is lacking. So, still need some time to make people adapt it especially the cost. 

YTL 4G service in Malaysia

Few years back, government had given WiMAX licences to few companies, they were P1, AMAX, REDtone and YTL. For the first three companies, they took the same strategy that was to provide the 4G service meanwhile expending their coverage gradually over time. But, YTL took a different approach by rolling out its coverage first before making their service available. So, YTL can be said that is late than its rivals about two years to public. But, by November 19 2010, YTL had launched YES 4G, and claiming that thier coverage in Peninsular Malaysia with more than 1000 sites. As comparison, P1 although they started their service earlier than YTL, it only current standing at 800 over sites over all Peninsular Malaysia except for Malacca. In the other words, YTL is standing a wider range and better position of market. This makes the 4G market more interesting.

The following diagrams showing available LTE service which is owned by YTL in specify states.

Selangor

Negeri Sembilan

Johor

Perak

Kedah

With continuous development, for those uncovered states, YTL also started to extend their network into them and increase coverage. For example, YTL Communications Sdn Bhd planed to add another 2000 to 3000 telecommunications tower sites throughout Peninsular Malaysia by end 2011. In Penang, YTLE also had invested over RM2 billion to build the 4G network and Yes would bring the power of mobile convergence to the people of Penang. For East Coast, YTL, had promised that, RM2 billion would be invested to increase the coverage of the 4G up to 80% by end of 2011. To claim the widest coverage in Malaysia, YTL also extended their network to Sarawak and Sabah in order to compete with other company like REDtone.

It is a healthy competition, every company thinking their own way and come out some plan thus benefit to public, that is giving us a high speed data transferring through 4G but enjoying the lowest price.

The Architecture of LTE Network and Working Principle

LTE is a standard for wireless data communications technology and an evolution of the GSM/UMTS standard. The main goals of LTE is to increase the capacity and data rates of wireless data networks, improve spectrum efficiency, improve coverage, reduced latency and packet-optimized system that support mutliple Radio Access. Thus, in order to achieve the goals, the architecture of the network if different from the previous wireless data transfer network, GPRS. So, in post, a comprehensive overview of the network architecture and basic working principle of LTE network is going to be discussed.

Basically, the LTE standard only supports packet switching with its all-IP network. The reason why LTE is designed only for packet switching is because it aims to provide seamless Internet Protocol (IP) connectivity between user equipment (UE) and the packet data network (PDN), without any disruption to the end users’ applications during mobility. Due to this characteristic, voice calls and text message natively (which are typically handled by circuit-switched networks like GSM and CDMA). In LTE architecture, Evolved UTRAN (E-UTRAN) is an important role which is the air interface of LTE upgrade path for mobile networks meanwhile it is accompanied by an evolution of the non-radio aspects under the term "System Architecture Evolution" (SAE), which includes the Evolved Packet Core (EPC) network. Together LTE and SAE comprise the Evolved Packet System (EPS). Besides that, LTE network uses an eNodeB (evolved node B, essentially an LTE base station), a MME (Mobile management entity), a HSS (home subscriber server), a SGW (serving gateway), and a PGW (a packet data network gateway). These are considered as part of the EPC except eNodeB.

First, let us look into EPS in detail, the following figure showing those elements in EPS network. 

In LTE, main function of EPS is to provide the user with IP connectivity to a PDN for accessing the Internet, as well as for running service such as Voice over IP (VoIP). An EPS bearer is typically associated with a QoS. Multiple bearers can be established for a user in order to provide different Qos streams or connectivity to different PDNs. Figure above shows the overall network architecture, including the network elements and the standardized interfaces. At a high level, the network is comprised of the CN (EPC) and the access network E-UTRAN. While the CN 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. This gives network operators the possibility to source different network elements from different vendors. In fact, network operators may choose in their physical implementations to split or merge these logical network elements depending on commercial considerations. 

The core network (called EPC in SAE) is responsible for the overall control of the UE and establishment

of the bearers. The main logical nodes of the EPC are:

• PDN Gateway (P-GW)

• Serving Gateway (S-GW)

• Mobility Management Entity (MME)

In addition to these nodes, EPC also includes other logical nodes and functions such as the Home Subscriber Server (HSS) and the Policy Control and Charging Rules Function (PCRF). HSS which contains users’ SAE subscription data such as the EPS-subscribed QoS profile and holds those information about the PDNs to which the user can connect, while PCRF is responsible for policy control decision-making, as well as for controlling the flow-based charging functionalities in the Policy Control Enforcement Function (PCEF), which resides in the P-GW. From the figure above, MME which is the control node that processes the signaling between the UE and the CN. The protocols running between the UE and the CN are known as the Non Access Stratum (NAS) protocols.

The main functions supported by the MME can be classified as:

• Functions related to bearer management – This includes the establishment, maintenance and release

of the bearers and is handled by the session management layer in the NAS protocol.

• Functions related to connection management – This includes the establishment of the connection and

security between the network and UE and is handled by the connection or mobility management

layer in the NAS protocol layer.

The access network of LTE, E-UTRAN, simply consists of a network of eNodeBs.For normal user traffic (as opposed to broadcast), there is no centralized controller in E-UTRAN; hence the E-UTRAN architecture is said to be flat. The eNodeBs are normally interconnected with each other by means of an

interface known as “X2” and to the EPC by means of the S1 interface — more specifically, to the MME by means of the S1-MME interface and to the S-GW by means of the S1-U interface. The protocols that run between the eNodeBs and the UE are known as the “AS protocols"

The E-UTRAN is responsible for all radio-related functions, which can be summarized briefly as:
• 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.
• Header Compression – This helps to ensure efficient use of the radio interface by compressing
the IP packet headers that could otherwise represent a significant overhead, especially for small
packets such as VoIP.
• Security – All data sent over the radio interface is encrypted.
• Connectivity to the EPC – This consists of the signaling toward MME and the bearer path
toward the S-GW.

For roaming architecture, it is shown as below:

For interworking architecture, it is shown as below:

Here is a video which briefly explain the overview of architecture of whole LTE network.

What actually 4G is?

Nowadays, 4G becomes one of the hot topic in telecommunication system. $G is the fourth generation of cellular mobile communications standards which is a successor of the third generation (3G) standard. With the move to the fourth generation (4G), there are a lot new emerging technologies and confusions coming along, for example, one of the emerging technologies like LTE and Mobile WiMax. So, it is important for us  to understand the 4G before we really go for those emerging technologies.

Basically, 4G is a technologies standard which has a set of requirements. In March 2008, the set of requirements for 4G had been specified by the International Telecommunication Union-Radio Communication Sector (ITU-R) and named it as IMT-Advance (International Mobile Telecommunications Advanced). A technology must fulfill the requirements then only can be said it is a 4G system. The following shows the requirements:

• Based on an all-IP packet switched network.

• Peak data rates of up to approximately 100 Mbit/s for high mobility such as mobile access and up to approximately 1 Gbit/s for low mobility such as nomadic/local wireless access.

• Dynamically share and use the network resources to support more simultaneous users per cell.

• Scalable channel bandwidth 5–20 MHz, optionally up to 40 MHz.

• Peak link spectral efficiency of 15 bit/s/Hz in the downlink, and 6.75 bit/s/Hz in the uplink (meaning that 1 Gbit/s in the downlink should be possible over less than 67 MHz bandwidth).

• System spectral efficiency of up to 3 bit/s/Hz/cell in the downlink and 2.25 bit/s/Hz/cell for indoor usage.

• Smooth handovers across heterogeneous networks.

• Ability to offer high quality of service for next generation multimedia support
.

So, since 4G just a standard or a reference for network developers to develop of their own technology, but why people always relate LTE to 4G as promoting it to public? The reason why the question appears in my mind it because LTE is only able to have a maximum peak download speed only rates at 100Mbit/s meanwhile peak upload speed only at 50Mbit/s, comparing to the requirement of 4G, it is still falling very far from it. The only possible answer to explain it is marketing issue, to attract the attention from the market, thus mobile phones and telecoms are forced to flaut their product as 4G in order to compete with their rivals. But luckily, a good news is coming, after some time, there will have a new technology is coming into the market, that is LTE Advanced, a actual technology which satisfies all the requirements of 4G. Public eventually can enjoy those benefits from real 4G network.

Overview of LTE network

Mobile broadband is a reality today and is growing  fast, as members of the internet generation grow accustomed to having broadband access wherever they go, and not just at home or in the office. By 2016 there are expected to be close to 5 billion mobile broadband subscriptions worldwide. The majority of these will be served by HSPA and LTE  networks. LTE is continuously being developed to make sure that future requirements and scenarios are being met and prepared for in the best way

So, what is LTE? LTE stands for Long Term Evolution, its full name is 3GPP Long Term Evolution for the Universal Mobile Telecommunications System, or 3GPP UMTS LTE for short. Basically, LTE is the 3rd Generation Partnership Project which under UMTS group ( a group responsible for standardzing and improving the Universal Mobile Telecommunications System). The reason why LTE is taken seriously because it provides several significant benefits to currently high demand on communication system.

The main benefits which are provided by using LTE system are:

• Higher Data Rates and Performance - It can be said so because one of the requirements on LTE is to provide a downlink peak rates at least 100Mbit/s. Thus, in LTE,  5-12Mbps in the forward link and 2-5Mbps in the reverse link can be easily achieved. Users will experience even better quality in interactive TV, mobile video blogging, advanced games, streaming and those activities involve in high bandwidth consumes.
• Security -  LTE provides enhanced security through the implementation of Universal Integrated Circuit Card (UICC) Subscriber Identity Module (SIM) and associated robust and non-invasive key storage and symmetric key authentication using 128-bit private keys.
• Wide range of terminals - In addition to various types of mobile devices and computer and consumer electronic devices will incorporate LTE embedded modules. Besides that, all these devices can have ubiquitous mobile broadband coverage from one day because LTE suppors handover and roaming to current mobile networks.