Sony Pixel Power calrec Sony

Circuit Switched vs Packet-Switched Networks

27/03/2025

Circuit switched networks physically connect two endpoints using a communication channel through the network. This utilises a fixed bandwidth for the session whilst the two endpoints remain connected. Packet switched networks offer the ability to split the communication channel into small packets to be sent across the network using multiple routes offering redundancy and increased performance. This utilises dynamic bandwidth management which can be optimised for each connected party and allows for many more services and connections to be active at the same time using the same bandwidth.

In the cellular network GSM (2G) and UMTS (3G) use circuit switching for voice, circuit switched dialup (CSD) and short messaging service (SMS) traffic and use packet switching for GPRS data traffic. In LTE (4G) the entire network uses packet switching and has no capability for circuit switched network support. As a result, the voice and SMS services must be moved over to a packet switched network when using the LTE (4G) network. In addition to this, CSD is no longer supported and GPRS data must be used instead.

Please see Circuit Switched Dialup (CSD) Migration to LTE Application Note' here.

Voice Overview Many applications in use today utilise voice as part of the service offering. This may be to connect two parties together to communicate such as in an elevator emergency failure system, to implement an automated payment service using a dial keypad or report a fault with a system using normal spoken language. Whatever the reason for using the voice service in a cellular system, there are some differences with the LTE network which are described in more detail below.

On legacy devices supporting GSM (2G) and UMTS (3G) services, the voice and SMS components of the system use circuit switching as the transmission channel. For GSM the whole system was built on an analogue infrastructure and digital data was added to the system later with the advance of GPRS packet data. The UMTS system is based on the GSM standard and therefore also supports both digital and analogue components. The UMTS framework allows much higher data rates over GSM but is still based on a similar infrastructure.

LTE on the other hand is entirely digital and has no analogue components at all. Therefore, new methods are used to take advantage of the new features offered by the LTE network as analogue voice calling is no longer possible and the packet switched network must be adopted.

VoLTE (Voice over LTE) Overview The LTE network supports voice and many other additional services in the same way as GSM and UMTS, however, as there is no analogue component the voice must be encoded and sent digitally across the network using packets. The 3GPP body have specified the voice service on LTE which is highly optimised and takes advantage of the additional bandwidth and low latency of the LTE network. This service is called Voice over LTE (VoLTE) and uses the digital packet switched network in a much more efficient way than traditional services. This means that VoLTE can support up to 3 times more voice capacity than previous UMTS networks and up to 6 times more capacity than older GSM networks.

The VoLTE service is provided on LTE over the IP Multimedia System (IMS) network service which is a standardized framework for delivering multimedia services over TCP/IP. It has been developed to allow all content rich media from wireless and wireline applications and allows for advanced services to be provided over the existing infrastructure without the need for individual control functions for each service.

The network provider must support IMS to be able to offer VoLTE as a service to its customers. The IMS framework must be integrated within the network's core architecture and is fundamental to the operation of the network.

Network Usage with Circuit Switch Fall Back (CSFB) With existing GSM (2G) and UMTS (3G) networks, the core functions are built into the application and can be supported with any hardware platform that supports voice and any SIM card that supports voice. This allows for a very simple implementation and calls can be established without any special configuration to the end equipment.

With newer modems that support LTE (4G) in addition to GSM (2G) and UMTS (3G) the firmware in the modem performs a subtle trick to continue having seamless voice support. When connected to the network for transmitting digital packet data, the unit connects to and uses the LTE network. When attempting to dial a voice number the unit automatically switches to UMTS (3G) or GSM (2G) to establish the call. Once the call is finished it reverts to the LTE network. This technology is called circuit switch fall back and is a short-term solution to allow all network providers to offer voice services on the LTE network whilst they implement their own full IMS solution.

This process is fine whilst there are UMTS (3G) and GSM (2G) networks available to use but the analogue networks are being gradually sunset to be replaced entirely with the LTE network.

With the LTE (4G) network it is necessary to configure the device to allow calls to be made using the LTE only network over the IMS service.

SMS Overview The short messaging service (SMS) can be used to send and receive small text messages which can be used in a variety of ways for applications that use the cellular network. The messaging service can be used to configure settings in remote equipment as well as reporting on the current configuration. In addition, the messaging service can inform users directly of a triggered alarm state or indicate when a certain criterion has been met. As with voice, the existing GSM (2G) and UMTS (3G) core functions are built into the system and can be supported with any hardware platform that supports the SMS messaging service and any SIM card that has SMS functio
LINK: https://www.siretta.com/2025/03/circuit-switched-vs-packet-switched-ne...
See more stories from sequoia

Most recent headlines

05/01/2027

Worlds first 802.15.4ab-UWB chip verified by Calterah and Rohde & Schwarz to be demoed at CES 2026

Worlds first 802.15.4ab-UWB chip verified by Calterah and Rohde & Schwarz to be ...

04/08/2026

Dalet Announces Commercial Availability of Dalia, Bringing Media-Aware Agentic AI to Enterprise Productions

Dalet, a leading technology and service provider for media-rich organizations, t...

04/07/2026

Detective Conan: Fallen Angel of the Highway Opens in Dolby Cinemas Across Japan, Presented in Dolby Atmos and Dolby ...

April 7 2026, 19:00 (PDT) Detective Conan: Fallen Angel of the Highway Opens in...

01/06/2026

Dolby Sets the New Standard for Premium Entertainment at CES 2026

January 6 2026, 05:30 (PST) Dolby Sets the New Standard for Premium Entertainment at CES 2026 Throughout the week, Dolby brings to life the latest innovatio...

27/05/2026

Telestream Appoints Benjamin Desbois as CEO, Effective July 1

Telestream has announced that its Board of Directors has appointed Benjamin Desbois as Chief Executive Officer, effective July 1, 2026. Desbois, currently Teles...

27/05/2026

FOX MLB Leads Live-Event Categories; ESPN Is Tops Overall at 47th Annual Sports Emmy Awards

ESPN garnered 10 awards; NBC's Sunday Night Football received the Outstandin...

27/05/2026

Matrox Video Marks 50th Anniversary, Announces New Product Launch for June

Matrox Video is celebrating its 50th anniversary, marking five decades of operations from its headquarters in Montreal, Canada. Founded in 1976, the company has...

27/05/2026

MLB Announces Fan Engagement Initiatives for Americas 250th Anniversary

Major League Baseball has announced a series of initiatives tied to America's Semiquincentennial, including a national marketing campaign, Fourth of July br...

27/05/2026

Advanced Systems Group Hires Brian Gross as Account Manager for Audio Team

Advanced Systems Group (ASG) has announced that Brian Gross has joined the company as an Account Manager on its Audio team, based in the Burbank office. He will...

27/05/2026

Nielsen Research: Hispanic Fans, Asian Markets Drive Global Soccer Audience Ahead of World Cup 2026

Nielsen has released new research on soccer fandom ahead of the FIFA World Cup 2...

27/05/2026

ESL FACEIT Group Debuts First Ever Esports Vertical Stream Co-Developed With TikTok

ESL FACEIT Group (EFG) has unveiled a new partnership with TikTok to bring broad...

27/05/2026

Two Weeks Away: FIFA Outlines Production Plans for Highly Anticipated North American-Based World Cup

FIFA's Oscar Sanchez gives a deeper look to how this tournament will be cove...

27/05/2026

SVG Students To Watch: Maggie Lynn, Virginia Tech

The soon-to-be senior from Charlottesville is building her skills in replay, TD, and even creative content for HokieVision and its ACC Network productions In t...

27/05/2026

A Global Festival of Football: FOX Sports Illustrates Strategy to Bring Every FIFA Mens World Cup Match to the U.S. Audience

FOX Sports' Mike Davies breaks down the vision for this summer's showcas...

27/05/2026

Top-Tier Storytelling: Host Broadcast Services Works at Capturing the Atmosphere of the FIFA Mens World Cup

HBS's Paul King, FIFA's Oscar Sanchez preview how the masses at home wil...

27/05/2026

Matt Gangl & Pete Macheska on FOX MLBs Huge Night and an Unforgettable Postseason Run

FOX's MLB coverage dominated the night at the 47th Annual Sports Emmy Awards...

27/05/2026

FOXs Mike Davies and Team on Outstanding Technical Team Win for 2025 World Series

One of the most memorable Postseasons in baseball history would have had no memo...

27/05/2026

NBC Sports Rob Hyland Reflects on an Unforgettable Sunday Night Football Season

NBC's Sunday Night Football is among the most decorated and most watched programs in the history of television. It added to its jam-packed trophy case on Tu...

27/05/2026

Prime Videos John Ward and Mike Francis on Groundbreaking NBA on Prime Video Studio

The 2026 Sports Emmys marked a watershed moment for Prime Video Sports. After bu...

27/05/2026

Countdown to FIFA World Cup 2026: SVG Launches SportsTechLive Blog in Lead-up to Winter Games

With the Opening Match just over two weeks away, the entire sports-production-te...

27/05/2026

Spotify Brings Long-Form Magazine Articles to Audio

Spotify already brings together listeners' favorite music, podcasts, and audiobooks in one place. Now, we're trialing a new format that expands the cont...

27/05/2026

Podcast Clips Make Your Favorite Moments Easier to Save and Share

The best podcast moments deserve more than just a mental note. That's why today, we're making those moments easier to save and share with clips. Whethe...

27/05/2026

Spotify and Netflix Partner With Jay Shetty to Bring On Purpose' to Video Across Both Platforms

On Purpose is one of the most popular podcasts in the world, known for conversat...

27/05/2026

Olivia Rodrigo Brings Billions Club Live to Barcelona: Watch the Concert Film Now

On May 8, 1,500 of Olivia Rodrigo's top fans gathered in Barcelona's Tea...

27/05/2026

JZ Microphones announce the MU-1

Hybrid design combines large-diaphragm capsule & ribbon JZ Microphones have teamed up with Grammy-winning producer and engineer Marc Urselli to develop a ne...

27/05/2026

Tape Effects Collection from AIR Music Tech

Three new plug-ins inspired by classic tape effects AIR Music Tech's latest release delivers a set of plug-ins that aim to capture the character, moveme...

27/05/2026

The Crow Hill Company's Absurdly Quiet Piano goes Pro

Piano played on the edge of silence The Crow Hill Company's Vaults collection offers a continual rotation of instruments that are given away for free fo...

27/05/2026

Arturia release Memory V

Recreates Moog's iconic Memorymoog polysynth Arturia's vast software instrument range offers a combination of new and old, with innovative modern so...

27/05/2026

Accentize introduce free dxLevel plug-in

Offers loudness levelling for speech and dialogue Accentize have built up a solid reputation with their audio-restoration tools, and their latest plug-in is...

27/05/2026

10,000 units strong - The Rohde & Schwarz R&S M3SR Radio 4400

10,000 units strong - The Rohde & Schwarz R&S M3SR Radio 4400 Rohde & Schwarz celebrates a major manufacturing milestone, producing its 10,000th R&S M3SR Radi...

27/05/2026

L3Harris Introduces the XL Converge 300P Portable Public Safety Radio

The XL Converge 300P radio system emerges with a groundbreaking feature set enhancing the mission-critical communications of public safety, federal and critica...

27/05/2026

Modernizing Public Safety Communications

Pairing Two47 MCX software with existing LTE networks means tailored system upgrades that can save time, money and lives....

27/05/2026

L3Harris Strengthens Global Solid Rocket Motor Supply Chain With New PAC-3 Propulsion Supplier

PAC-3 MSE offers improved range, speed, and maneuverability, making it an effect...

27/05/2026

Brightcove Adds New Features to Its AI Suite for Video Advertising

Share Copy link Facebook X Linkedin Bluesky Email...

27/05/2026

Star Trek VFX: Recreating John Knoll's Iconic Warp Stars without a Slitscan Camera

Star Trek VFX: Recreating John Knoll's Iconic Warp Stars without a Slitscan ...

27/05/2026

Adventure World Uses Blackmagic Replay for Marine Live

Adventure World Uses Blackmagic Replay for Marine Live Brie Clayton May 27, 2026 0 Comments Large screen displays and slow motion replays dynamically ...

27/05/2026

Berklee Alumna and Assistant Professor Olivia Prez-Collellmir to Premiere Original Work at Gaud Centennial in Barcelona

Berklee Alumna and Assistant Professor Olivia P rez-Collellmir to Premiere Origi...

27/05/2026

Gravity Media Expands Into Creative Services With New Agency

Share Copy link Facebook X Linkedin Bluesky Email...

27/05/2026

Tegna Names Patrick Paolini as CEO

Share Copy link Facebook X Linkedin Bluesky Email...

27/05/2026

Telestream Taps Company Vet Benjamin Desbois as CEO

Share Copy link Facebook X Linkedin Bluesky Email...

27/05/2026

HDR10+ Technologies to Launch Eclipsa Video Certification Program

Share Copy link Facebook X Linkedin Bluesky Email...

27/05/2026

ATSC to Gather in Washington Next Week for Annual Meeting

Share Copy link Facebook X Linkedin Bluesky Email...

27/05/2026

Telestream Appoints Benjamin Desbois as Chief Executive O...

Co-founder Dan Castles to transition to Executive Chair; internal promotion reinforces continuity and long-term growth Telestream, a global leader in media wor...

27/05/2026

Big Blue Marble Announces First End-to-End 5G Broadcast S...

Big Blue Marble today announced that its Nakolos platform is the first end-to-end 5G Broadcast solution worldwide to implement the complete feature set introduc...

27/05/2026

Lightware Continues Its ESG Commitment Through Girls Day...

Lightware recently hosted the Girls' Day event in April at its headquarters in Budapest, welcoming students for an interactive introduction to engineering a...

27/05/2026

VEON's Kyivstar and Uklon Launch Ukraine's First Live Testing of Autonomous Vehicle Technology

27 May 2026 VEON's Kyivstar and Uklon Launch Ukraine's First Live Testi...

26/05/2026

Matrox Video Marks 50 Year Milestone

Share Copy link Facebook X Linkedin Bluesky Email...

26/05/2026

Roku Expands Premium Subscriptions With Fox One

Share Copy link Facebook X Linkedin Bluesky Email...

26/05/2026

Brian Gross Joins ASG's Audio Team as Account Manager

Share Copy link Facebook X Linkedin Bluesky Email...