4G, Long Term Evolution (LTE), VOLTE and VOWifi

LTE stands for Long Term Evolution and is a registered trademark owned by ETSI (European Telecommunications Standards Institute) for the wireless data communications technology and a development of the GSM/UMTS standards.

  • Both radio and core network evolution
  • All-IP packet-switched architecture
  • standardised by 3GPP
  • lower CAPEX ans OPEX involved

LTE evolved from an earlier 3GPP system known as the Universal Mobile Telecommunication System (UMTS), which in turn evolved from the Global System for Mobile Communications (GSM). Also it is aligned with 4G (fourth-generation mobile)

It is backward compatible with GSM/EDGE/UMTS/CDMA/WCDMA systems on existing 2G and 3G spectrum, even hand-over and roaming to existing mobile networks.

Motivation for evolution – Wireless/cellular technology standards are constantly evolving for better efficiency and performance.LTE evolved as a result of rapid increase of mobile data usage. Applications such as voice over IP (VOIP), streaming multimedia, videoconferencing , cellular modemetc.

It provides packet-switched traffic with seamless mobility and higher qos than predecessors. Also high data rate, throughput, low latency and packet optimized radioaccess technology on flexible bandwidth deployments.

Timeline of Evolution 

  • GSM  : calls  on circuit switching ( CS ) between 2 parties for communication. Dedicated circuits are used for voice and SMS.
  • GPRS : packet switching (PS) is introduced for data services
  • UMTS / 3G : network elements begin evolving into PS . No changes to core.
  • EPC / LTE/VOLTE : No circuit switched domain at all .

Performance

Peak Data Rate

  • uplink – 75Mbps(20MHz bandwidth)
  • downlink – 150 Mbps(UE Category 4, 2×2 MIMO, 20MHz bandwidth) , 300 Mbps(UE category 5, 4×4 MIMO, 20MHz bandwidth)

Carrier bandwidth

Range from 1.4 MHz up to 20 MHz. Ultimately bandwidth used by carrier depends on frequency band and the amount of spectrum available with a network operator

Mobility 350 km/h

Multiple Access Schemes

  • uplink: SC-FDMA (Single Carrier Frequency Division Multiple Access) 50Mbps+ (20MHz spectrum)
  • downlink: OFDM (Orthogonal Frequency Division Multiple Access) 100Mbps+ (20MHz spectrum)
  • Multi-Antenna Technology , Multi-user collaborative MIMO for Uplink and TxAA, spatial multiplexing, CDD ,max 4×4 array for downlink

Coverage

  • 5 – 100km with slight degradation after 30km
  • LTE architecture supports hard QoS and guaranteed bit rate (GBR) for radio bearers.

Technology

All interfaces between network nodes are IP based
Duplexing – Time Division Duplex (TDD) , Frequency Division Duplex (FDD) and half duplex FD

MIMO ( Multiple Input Multiple Output ) transmissions –

Allows the base station to transmit several data streams over the same carrier simultaneously.
Modulation Schemes

QPSK, 16QAM, 64QAM(optional)

LTE Architecture

Primarily composed of

User Equipment (UE)

  • Mobile Termination (MT)
  • Terminal Equipment (TE) 
  • Universal Integrated Circuit Card (UICC) : also known as the SIM card for LTE equipments. It runs an application known as the Universal Subscriber Identity Module (USIM).

2. Evolved UMTS Terrestrial Radio Access Network (E-UTRAN)

handles the radio communications between the mobile and the evolved packet core. High level representation for  eNodeB or eNB

Role of eNB : sends and receives radio transmissions to all the mobiles using the analogue and digital signal processing functions of the LTE air interface. eNB also controls the low-level operation of all its mobiles, by sending them signalling messages such as handover commands.

3. Evolved Packet Core (EPC)

This sub system resembles IMS environment.

Packet Data Network (PDN) Gateway (P-GW) communicates with the outside world simillar to GGSN ( GPRS support node ) and SGSN ( serving GPRS support node ) in UMTS and GSM.

Home Subscriber Server (HSS) is a central database that contains information about all the network operator’s subscribers. Almost simillar to HLR/AAA in 2G /3G architcture.

Mobility management entity (MME) controls the high-level operation

For a roming user in Visited-PLMN , he is connected with the E-UTRAN, MME and S-GW of the visited LTE network. However, LTE/SAE allows the P-GW of either the visited or the home network to be used, as shown in below:

For roaming prepaid charging , accounting flows are made to access prepaid customer data, via P-Gateways or CSCF in an IMS environment.

LTE-Advanced

LTE devices capable of CAT6 speeds (Category 6 )
Increased peak data rate – downlink 3 Gbps, Uplink 1.5 Gbps ( 1 Gbps = 1000 Mbps)
Spectral efficiency from 16bps/Hz in R8 to 30 bps/Hz in R10
Carrier Aggregation (CA)
Enhanced use of multi-antenna techniques
Support for Relay Nodes (RN)

References

Read More

Also read about previous generations of telecom namely 2 G and 3G

2G to 3G – generation of telecom

Where 2G is referred to as the GSM era , 2.5 G as the GPRS with GSM era. As compared to its predecessor 1G which used FDMA ( Frequency Division Multiplexing ) for channelization , 2G used used TDMA and CDMA for dividing the channels .


Internet Telephony Convergence- JAINSLEE Platform

Convergence : Telephone networks and computer networks converging into single digital network using Internet standards.

Components in a Network

  • Client computer
  • Server computer
  • Network interfaces (NICs)
  • Connection medium
  • Network operating system
  • Hub or switch
  • Routers- Device used to route packets of data through different networks, ensuring that data sent gets to the correct address

1

Figure :simple computer network, consisting of computers, a network operating system residing on a dedicated server computer, cable (wiring) connecting the devices, network interface cards (NICs), switches, and a router.

2

Figure of a Enterprise Network : local area networks (LANs) linked to enterprise level / corporate network . It consists of :

  • Powerful servers
  • Web site
  • Corporate intranet, extranet
  • Backend systems
  • Mobile wireless LANs (Wi-Fi networks)
  • Videoconferencing system
  • Telephone network
  • Wireless cell phones etc

The convergence of Internet and Telephony opens up new revenue streams for the Communication Service Providers by delivering new innovation based convergent applications.

Before discussing digitization of Communication and telecom we need to first understand packet switching .

What is Packet switching ?
It is a method of slicing digital messages into packets, sending them along different communication paths as they become available. Then reassembling these received packets at destination. It is a more efficient use of network’s communications capacity.
Previous circuit-switched networks required assembly of complete point-to-point circuit.

What triggered this Technology development?

The Internet, IPTV and Social Media networking is evolving dynamically in the end user space of Communication Service Provider. This opens door for delivering new innovative services to end user through these converged applications.

A SP( Service provider ) has to work with multiple Communication Providers globally and based on the experience with the customers, has to conceptualize and implemented new innovative use cases on open platform to reduce the cost and  migrate from legacy to Next Generation Networks.

What does convergence mean to

  • Equipment Vendors / EV
    • Femto / FMC
    • Challenges in System Integration
    • Box to Solution Sales
    • Services software based
  • Enterprises
    • Low Capex – Hosted Models
    • Enterprise Mobility
    • IP Enabled Services
    • UC to UC
    • Web Integration with Mobility
  • Telco
    • Enterprise communication will be a big focus Area
    • Push to EVs for CAPEX
    • Wish to leverage Legacy as well
    • Challenges in Vertical Solutions
    • Will face challenges by OTT players

 

What will it do, how and in which situation ?

The underlying technology of Internet Telephony Convergent Platform is JAIN SLEE Framework which is open standard for developing core network based applications. It enables development of network agnostic applications , implemented through resource adapters for deploying same applications over different networks like SIP/IN etc.

JAINSLEE framework provides capability to form new complex services through reusable service building block in much easier way then traditional methods. This reduces cost for launching new services and bundled different services into the new convergent service in network agnostic way. 

It also bring benefits in term of reducing the dependency on Vendor proprietary platform and eventually bringing down cost involved and Time to market in launching new service.

The OpenCloud Service Layer   OpenCloud

picture courtesy : Opencloud.com

What problem does this technology seek to solve?

Today communication service provider are facing vendor locking situation where most of services deployed are platform dependent which requires huge cost of investment for launching new services. Traditional service development platforms are major roadblock for operators to launch new collaborative services which involves both voice and data channels as they are not based on open standards and are tied to the vendor specific technologies. Also in a fast changing technology the operators need to switch their focus on new innovative services through which operator can monetize services and provide the value added experience to their end customers. To enable it we proposed and implemented framework which not only act as the new Internet Telephony convergent platform but also in sync with their future network transformation strategy as it is based on open standards. Through this platform same applications can be targeted to different segment of users with minimal cost impact. Some of the application which we have developed are detailed below.

a) Parental Control is an application through which parents can have control over their children’s Internet video on demand request. Once a child requests for any video, preview of the same(short clip of video) at the same instance is send to parents’ smart phones. Parents can see preview and can decide there and then weather it is adequate for his/her kids or not, and can either allow or deny through his mobile.

b) IPTV/VOD session mobility is a service which allow user to transfer their ongoing voice call/video-on-demand session from their smartphone to desktop/computing device/smart-device and vice-versa seamlessly.

c) Converged application like unified communication platform for trader community take advantage of both voice and data services and help trader community in terms of analytics and decision making process.

What is the specific breakthrough of this technology?

Internet and Telephony are two major drivers in Telecom domain. Hence the concept of convergence of Internet and Telephony is of great interest for the Telcos. Internet telephony, also known as voice-over-IP or IP telephony is the real-time delivery of voice between two or more parties, across networks using the Internet protocols, and the exchange of information required to control this delivery. New innovative use case scenarios  have been conceptualized and implemented considering new user behavior changes. These bring in value addition to CSPs in order to bring more revenue streams. Solutions like Secure VOIP bring another dimension of innovation as it provides a secured voice communication over the internet using open source software like Asterisk. This solution helps business reduce their operational communication costs using encrypted standard security algorithms.

Asterisk- Applications (1)

pic courtesy : asterisk.com

How does this technology compare with other technologies? 

Internet telephony convergent platform has the unique value proposition based on new innovative use case scenarios using multiple underlying technologies. These scenarios are implemented using Open Standards. Though many other vendors’ platform also provides some of the facilities of platform in part and pieces but none of them give complete end to end solutions suits to operators as our Internet Telephony convergent platform provides.

How does it help in achieving the goals?

We consider it as solution which can act as foundation block to build a long term partnership with operators especially in area of services landscape. This solution enables operator to monetize different voice and data convergent services and in sync with the operator’s next generation transformation initiative. The services acts as catalyst to increase the data usage of end-users. Strong business case can be built with these services by operators as they meet the future demands of tech savvy end users. These services not only fill the void between communication service provider and social media/internet/video-on-internet but also take advantage of reach of social media/internet and eventually enable operator to add new revenue stream. These services can also help operator to increase their brand visibility with added advantage of social media and internet application bundled with their core services. Operator can charge it on per application basis or can be just carrier and charge for data usage. Convergent services which involves both the voice and data, enable operator to charge on voice services , data services and application usage. With our rich experience in convergent platform domain we believe we can convert significant opportunities in this space.

Explain your journey of Technology development ?

After seeding of concept of Internet Telephony convergent platform SP should explore partner product Software centric platforms like Open cloud, Oracle, Mobicient etc which offers the capability to deliver convergent applications at a low cost and using the open standards. Standards like JAIN SLEE provide capability for developing and delivering such applications across different type of underlying network. 

Mobicents Platform

pic courtesy : Mobicents.com

One can develop the complete solution using such open, standard platforms as a base . The complete solution takes care of the real-network issues and solutions for the same. There were many hurdles and roadblock at first. Adaptation to open standards like JAIN SLEE requires fast ramp up as it is quite complex technology. In a small stipulated time a core team should have developed competency through Partner Training inputs and Brain Storming sessions. To test framework at lab, there would be dependency on many open source software and strategic partner products. There would be many incompatibility issues. Its important that such issues be  sorted out by exhaustive explorations of products and by bug fixes .

Benefits expected if this Technology is implemented / commercialized 

a) Communication service providers are able to realize appreciable cost saving through Internet Telephony convergent platform Operators deployed in their network. This is so legacy platform were costly and difficult to manage. This platform brings innovative and cost effective way of launching new collaborative services which brings new revenue stream.

b) Improved Time to market

c) Extensible architecture for the service helps in extending the service for multiple markets.

Social Benefits

Unified communications, where voice, video, email, text and other messaging technologies are combined to provide greater flexibility for users by enabling new ways to transfer information and manage connectivity. Integration of collaborative services with the social media platform like Facebook , Linkedin , Twitter etc, increases the connectivity and value experience of end users. Through social media based convergent applications operator can further increase their reach to end users by utilizing underlying the Internet Telephony convergent platform.

My Insights 

Based on my personal experience while implementing this technology/platform, I think this solution act as catalyst for enabling the transition from network eccentricity to customer eccentricity. This movement is further supplemented through the reduced dependence on legacy vendors and increased adoption of open standard based platforms. Through the converged application layer for Telcos I envisage a platform which is agnostic to underlying network layer. Unified platform allows carriers, mobile operators, and cable operators to rapidly create, manage, and deliver converged video, voice, and data service bundles across multiple networks and devices. It enhance end user experience and enable Telcos to add new revenue stream by offering value added services to their customer.