- Access Layer
- Transport Layer
- Session Layer
- IR 92 IMS
- IR 94 Profile for Video Services
- Enterprise communication systems
From ARPANET(Advanced Reseracha nd Prjects Agency Network) in 1973 by US dept of defence , invention of HTTP in 19196 and finally evoluation of SIP in 2000 and availiability of broadband ethernet services, the telecom landscape has evolved. As far as infrastructure, services, and contents are concerned, the VoIP industry is witnessing a migration from POTS / PSTN/ Legacy integrations to NGN (Next Generation Network).
NGN was implemented globally as a means to change the cost base, agility and service capabilities of telecoms providers. The evolved architecture for the transition is one that provides flexibility to service providers by enabling them to deploy new services on IP based technologies, while leveraging existing services and infrastructure as long as it makes sense. This post describes the evolution of voice communication in access , transport and session layers respectively.
|Year of dev||1970-1984||1980-1999||1990-2002||2002-2010||2010-2015|
|Launch year||1987 by Telstra Australia||1991 in Finland by Elisa||1998 pre-commercial launched by NTT DoCoMo in Japan , branded as FOMA.||2009 in Stockholm (Ericsson and Nokia Siemens Networks systems)||2019, in South Korea,|
|Techology||AMPS, NMT , TACS||GSM||WCDMA||LTE, WiMAX||MIMO , mm Waves|
|Frequency||30 Khz||1.8 Ghz||1.6 – 2 Ghz||2- 8 Ghz||3 – 30 Ghz|
|bandwidth||2.4 Kbps||14.4 – 50 Kbps ( GPRS)|
64 Kbps – 1 Mbps ( EDGE)
|144 Kbps – 2 Mbps||100 Mbps – 1 Gbps||> 1Gbps |
upto 35.46 Gbps
We see that the speed enhances considerably with every generation- 1G offerd 2.4 kbps, 2G offered 64 Kbps based on GSM, 3G offered 144 kbps – 2 mbps whereas 4G offers 100 Mbps – 1 Gbps with LTE technology.
It is to be noted that one of requirements set by IMT-2000 was that speed should be at least 200Kbps to call it as 3G service and 384kbps ( wth stationary speeds of 2Mbps) for a “true” 3G.
Note that voice calls in GSM, UMTS and CDMA2000 were circuit switched but with newer technology voice calls became packet switched too and a lot of rereginerring was required.
LTE (Long Term Evolution) is a series of upgrades to existing UMTS technology involving OFDM and MIMO and newer upgrade were called LTE advanced also. Upcoming 5G offers speeds upto 35.46 Gbps.
While 2G introduced services like SMS , MMS , internal roaming , conference calls, call hold and billing based on services e.g. charges based on long distance calls and real time billing which were unheard of in 1G , there were challenges in terms of page load speed for interactive websites .
As 3G came into picture, usecases also enhanced with multimedia features siuch as fast web browsing, maps navigation, email, video downloading, picture sharing and other Smartphone technology
Read more about IMS ( IP multimedia System ) IP Multimedia Subsystem ( IMS )
It is noteworthy that SKYPE provided VoIP services ( since 2003) much before mobile phone had 2G/3G ( 2010). In current times with many fantastic options to choose from( whatapp , FB messenger , insta cht , Viber , Hangouts ..) given the high bandwidth with 4G/5G and mych advanced media / signal processing tech , the glocal voip scene is touching 400 mililion subscribers and looks very attractive with 1.5$ billion market.
Bodies and projects behind the evolutions
The GSM Association (GSMA) of mobile operators and related companies are devoted to supporting the standardising, deployment and promotion of the GSM mobile telephone system. The GSM Association was formed in 1995. It organises GSMA Mobile World Congress, in addition to smaller, targeted events GSMA Mobile Asia Expo and the GSMA NFC & Mobile Money Summit. Spanning more than 220 countries, the GSMA unites nearly 800 of the world’s mobile operators, as well as more than 200 companies in the broader mobile ecosystem, including handset makers, software companies, equipment providers, Internet companies, and media and entertainment organisations.
The 3rd Generation Partnership Project (3GPP) is a collaboration between groups of telecommunications associations, known as the Organizational Partners. The initial scope of 3GPP was to make a globally applicable third-generation (3G) mobile phone system specification based on evolved Global System for Mobile Communications (GSM) specifications within the scope of the International Mobile Telecommunications-2000 project of the International Telecommunication Union (ITU). The scope was later enlarged to include the development and maintenance of the Global System for Mobile Communications (GSM) including GSM evolved radio access technologies (e.g. General Packet Radio Service (GPRS) and Enhanced Data Rates for GSM Evolution (EDGE)) an evolved third Generation and beyond Mobile System based on the evolved 3GPP core networks, and the radio access technologies supported by the Partners (i.e., UTRA both FDD and TDD modes). It is an evolved IP Multimedia Subsystem (IMS) developed in an access independent manner
3GPP standardization encompasses Radio, Core Network and Service architecture. The project was established in December 1998 and should not be confused with 3rd Generation Partnership Project 2 (3GPP2), which specifies standards for another 3G technology based on IS-95 (CDMA), commonly known as CDMA2000. The 3GPP support team (also known as the “Mobile Competence Centre”) is located at the European Telecommunications Standards Institute (ETSI) headquarters in Sophia-Antipolis (France).
The Open Mobile Alliance (OMA) is a standards body which develops open standards for
the mobile phone industry. Network-agnostic : The OMA only standardizes applicative protocols; meant to work with any cellular network technologies being used to provide networking and data transport. These networking technology are specified by outside parties. In particular, OMA specifications for a given function are the same with either GSM, UMTS or CDMA2000 networks.
Legal status :The OMA is a British limited company.
Standard specifications The OMA maintains a number of specifications, including
- Browsing specifications, now called “Browser and Content”, previously called WAP browsing. In their current version, these specifications rely essentially on XHTML Mobile Profile.
- MMS specifications for multimedia messaging
- OMA DRM specifications for Digital Rights Management
- OMA Instant Messaging and Presence Service (OMA IMPS) specification, which is a system for instant messaging on mobile phones (formerly known as Wireless Village).
- OMA SIMPLE IM Instant messaging based on SIP-SIMPLE
- OMA CAB Converged Address Book, a social address book service standard.
- OMA CPM Converged IP Messaging
- OMA Client Provisioning (OMA CP) specification for Client Provisioning.
- OMA Data Synchronization (OMA DS) specification for Data Synchronization using SyncML.
- OMA Device Management (OMA DM) specification for Device Management using SyncML.
- OMA BCAST specification for Mobile Broadcast Services.
- OME RME specification for Rich Media Environment.
- OMA PoC specification for Push to talk Over Cellular (called “PoC”).
- OMA Presence SIMPLE specification for Presence based on SIP-SIMPLE.
- OMA Service Environment
- FUMO Firmware update
- SUPL, an IP-based service for assisted GPS on handsets
- MLP, an IP-based protocol for obtaining the position/location of mobile handset
- WAP1, Wireless Application Protocol 1, 5-layer stack of protocols
The IP Multimedia Subsystem (IMS) Profile for Voice and SMS, documented in this Permanent Reference Document (PRD), defines a profile that identifies a minimum mandatory set of features which are defined in 3GPP specifications that a wireless device (the User Equipment (UE)) and network are required to implement in order to guarantee an interoperable, high quality IMS-based telephony service over Long Term Evolution (LTE) radio access. The scope includes the following aspects:
· IMS basic capabilities and supplementary services for telephony.
· Real-time media negotiation, transport, and codecs.
· LTE radio and evolved packet core capabilities.
· Functionality that is relevant across the protocol stack and subsystems.
This document defines a voice over IMS profile by listing a number of Evolved Universal Terrestrial Radio Access Network (E-UTRAN), Evolved Packet Core, IMS core, and UE features which are considered
essential to launch interoperable IMS based voice. The defined profile is compliant with 3GPP specifications.
On premise private branch exchanges ( PBX ) were the first kind of business telephone systems to which the analog PSTN systems of the company were conneced. These analog circuits were then replaced by digital PBX which provided enhanced features liek screening , voicemails , shared lines.
In the current landscape , the digital PBX of the company is connected to the external telco privider via a SBC or SIP trunking service .
An ompremise LAN based voIP system can be accessed from outside via a VPN on SSL/ IPsec. Although it incures greater CAPEX but ensufe maximum control and ownership of the data . Many time the local laws mandate the server to be hosted with a partuclat geographical area too where an on premise setup and data centre is used.
Enterprise communication shifts from on-premise to SaaS (cloud)
As for remote worksforce and employees working from home (such as during lockdown , pandemics ) it is even more crticial for enterprises to maange inter communication between teams and keep the communication private ie not using piblic messaging platforms , hence the role of cloud based PBX integrated with secure and end to end encrypted telco providers is of prime importance .
To read how a SME can setup their own flexible and scable enterprise comunication system read –
VoIP/ OTT / Telecom Solution startup’s strategy for Building a scalable flexible SIP platform https://telecom.altanai.com/2013/11/21/what-should-a-telecom-solution-startup-do/
With the advent of other disruptive technologies such as free and opensource codecs in browser with WebRTC and well defined framework and standards, voIP definetly looks detsined to expand by leaps and bounds.