TDM (time division multiplexing) is a traditional form of call communication, a network that operates by transmitting analogue signals over a physical network of phone lines. With time, many such solutions have been replaced by more advanced communication networks, for example, VoIP. Voice over Internet Protocol (VoIP) is a unified communication network that works by using IP technology. With VoIP, your business can make and receive internet calls, media, voice messages, texts, and files.
When we discuss TDM and VoIP side by side, it gets easier to decide on which of the two options could prove to be better for your business. That’s exactly what we will be doing today, to understand the differences between TDM and VoIP.
What is VoIP?
Let’s circle back to the concept of VoIP technology and what exactly it is. VoIP allows you to use your daily internet connection for exchanging voice calls, but not limited to it. You can also make international calls, video calls, video conferencing, text messaging, call queuing, file sharing, and more.
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How does VoIP technology work?
VoIP uses the infrastructure capacity of an IP network to access communication over large distances. This means that there is no need to set up a physical connection via wires, which would be traditionally done to achieve a connection from one point to another.
To set up a basic VoIP system, you only need a few components. One of them is the internet, as the connection quality entirely depends on it. Other than that, you need a subscription to a VoIP service and a device to operate it on. VoIP can work on any device, whether that be a smartphone, laptop, tablet, or a traditional landline phone with an attached VoIP adapter.
The transmission of VoIP data can be explained to take place in three simple steps:
- For the first step, a call is initiated at one end of the connection. Any type of audio consists of analogue signals, which are converted into digital ones.
- These digital signals are sent to the network of your VoIP service provider. Here, they are converted into IP packets. Using compression and decompression algorithms, huge data take the form of packets, which use less internet bandwidth to travel.
- For the last step, these digital packets reach the other end of the connection and are converted back into audio signals. A clear sound is then heard via the speaker of the device being used.
What is TDM?
Time division multiplexing is a service used to make traditional phone calls over an analogue system. That means that a physical connection of copper wires is established between two points of connection. These copper wires are the same ones used in landline telephony.
Understanding the working of TDM
TDM transmits voice signals over dedicated time slots. This means that TDM only works with the exchange of voice data. Unlike VoIP, where video calls and file sharing are possible too, the same is not the case with TDM.
In Time Division Multiplexing, each call is given a fixed time slot. These time slots repeat continuously, making it seem like there are no breaks in the conversation. So even if no one is talking during their slot, the time is still taken up. This makes TDM more costly and less efficient for businesses with lower call requirements.
VoIP vs TDM: A Summary
| Aspect | TDM | VoIP |
|---|---|---|
|
Technology |
Uses analogue signals over copper wires. |
Uses IP technology over the Internet. |
|
Communication Type |
Only supports voice calls. |
Supports voice, video, text, and file sharing. |
|
Transmission Method |
Fixed time slots, even if unused. |
Sends data only when speaking. |
|
Hardware Requirements |
Requires specific PSTN hardware. |
Compatible with various internet-based devices. |
|
Integration |
No integration with other systems. |
Integrates with business apps and processes. |
|
Management |
On-site actions by professionals. |
Remote management via cloud-based tools. |
|
Scalability |
Lines bought in fixed sets (e.g., 23, 46) |
Add or remove users easily. |
|
Flexibility |
Location-bound due to physical wires. |
Accessible anywhere with internet.
|
|
Efficiency |
Time slots can go unused. |
Sends compressed data as needed. |
5 Key Differences between TDM and VoIP explained
Hardware requirements
- VoIP requires hardware that is easy to integrate and use with each other. You could get an internet connection from one service provider, your VoIP subscription from another, and easily use them with each other.
- On the other hand, TDM service providers provide you with a PSTN network along with all the required devices and technical support. You cannot mix and match different hardware because the integration capacity is minimal in this case.
Management and updates
- VoIP is a cloud-based software, and so the management actions (adding or removing users, overseeing operations, reporting problems, updating software, or integration) can be managed remotely.
- In case of TDM, all the administrative actions need to be done on-site. Plus, they require professionals, either the IT team of the business or the service provider. Ultimately, in this case, a maintenance charge would occur, too.
Scalability
- TDM is a traditional telephony method that does not have room for growth with business requirements. You can only purchase TDM lines in a set of 23. If your call capacity is less than that, the unused capacity will go to waste. Similarly, if you want to purchase more than 23 lines, the next possible amount is 46. Also, these lines are installed per user by the professional staff of your provider. There are a lot of technical steps involved, which incur an installation cost in a lot of cases.
- As opposed to TDM, adding and removing users from the system becomes easier with VoIP. Since there are no installation costs involved, the overall expense of using VoIP is lower than TDM, too.
Integration with business operations
- VoIP can integrate with existing business processes and applications, like sales and customer departments. This integration allows you to make direct calls within the software and generate call analytics reports.
- TDM doesn’t have any capacity to integrate with business applications. This is one of the main reasons why businesses prefer VoIP over TDM. It is because TDM cannot be implemented over IP technology, and there are already better alternatives available for the service.
Flexibility for remote teams
- VoIP supports remote teams to work flexibly. As long as an internet connection is available, VoIP calls can be made and received via software-based IP phones. So there is no need to carry heavy hardware around.
- In case of TDM, users are restricted to a specific location to make and receive calls. This is because the devices are connected to the system via physical wires that can not be extended or moved around.
Why TDM Phone Systems Have Become A Thing Of The Past
Although TDM was the mainstay of enterprise communications for decades, it is not sufficient today; modern business has outgrown this legacy infrastructure fundamentally. This is why progressive businesses are moving away from TDM systems.
Here are some key factors that have made TDM obsolete:
Vendor Lock-In
Conventional TDM networks result in vendor lock-in at an end-to-end level. You are locked into proprietary hardware, custom handsets, and expensive service contracts from the original provider.
Mixing gear from various providers will be impossible. More importantly, all of the major vendors, such as Samsung, have already ceased marketing and supporting their TDM-based product offerings.
Remote Work Incompatibility
The fact is that TDM binds employees to their desks. Each user is wired to one of the PBX cabinet’s ports. In an age where the majority of people work remotely, that’s a significant business disadvantage.
TDM solutions do not have nuance for softphones, mobile apps or reach-me-anywhere calling, something that is now indispensable to support the new world of work flexibility and business continuity.
Costly and Inflexible Scaling
The growth of a TDM system is inflexible and costly. You must acquire capacity in large, pre-set increments; for example, you must purchase 23 lines at a time, which constitutes a complete PRI circuit. If you have 25 lines for your business, you pay for 46.
This chunk scaling results in overprovisioning and waste. You need to get new equipment installed, a professional wiring job, and coordination with the service provider, who often takes days or weeks.
The Integration Gap
Modern business tools, customer-relationship management systems such as Salesforce, collaboration suites such as Microsoft Teams, and customer service software are built to mesh with communications systems. TDM’s silo architecture either does not permit such integration or makes it prohibitively expensive.
This, however, leads to workflow silos where staff are required to manually move data between systems and results in a lower efficiency and higher error rates.
Detailed Advantages And Disadvantages of VoIP and TDM
In order to choose the best business phone system for your company, you need to know the pros and cons of these technologies. VoIP is undoubtedly the future, but appreciating the strengths of TDM helps us understand why many businesses have been reluctant about making a transition.
Advantages Of TDM
- High-Quality Calls: Using an analogue signal over TDM, it delivers clear sound without compression or latency via a dedicated copper line. TDM used to be the industry standard for companies that prioritise call clarity.
- Simple To Use: TDM is old technology, and it’s simple. There are no tangled networks to configure, and troubleshooting isn’t all that difficult for properly trained engineers.
- No Internet Dependency: TDM systems do not rely on an internet connection, so there’s no need to worry about bandwidth or internet downfalls affecting your level of service.
- Reliable Quality: TDM systems do not rely on an internet connection, so there’s no need to worry about bandwidth or internet downfalls affecting your level of service.
Disadvantages Of TDM
- No Advanced Features: TDM is restricted to phone calls. There’s no integrated video conferencing, instant messaging and presence or business application integration.
- Costly to Scale: The upgrade of phone lines needs wireline engineers, hardware, and sometimes PBX updates, which cost thousands of pounds. The process can take weeks.
- No Business Integration: TDM cannot integrate with your CRM system, help desk, or other business applications.
- Outdated Technology: The UK PSTN switch-off means the traditional TDM network is no longer supported. Spare parts are becoming increasingly hard to find, and engineers with TDM know-how are retiring.
Advantages of VoIP
- Significantly Less Expensive: Nearly all VoIP tariffs have free UK calls, and international rates are much cheaper than TDM. There are no per-line rental charges or costly, long-term maintenance contracts associated with VoIP.
- Infinite Scalability: Add or subtract users in seconds via a web portal. There is no need for engineers, no hardware to buy, and no waiting. Easily expand to 5 to 500 users with a few clicks.
- Advanced Features: When it comes to phone features, VoIP has you covered: call recording, voicemail-to-email, auto-attendants and call queues, as well as video conferencing, instant messaging, presence indicators, mobile apps, and more, are all typically included at no extra charge.
- Ideal for Remote Workers: With the same business number, remote staff can make and receive calls from any location. The smartphone app provides a desktop-like experience on your device.
- Future-Proof Technology: VoIP systems are constantly updated with new features and security patches. With technology advancements, your system is future-proofed without the need to replace hardware.
Disadvantages Of VoIP
- Dependence on the Internet: VoIP is dependent on a reliable internet connection. When your broadband goes out, so does your phone system. You can mitigate this disadvantage with backup internet connections, but it’s another factor to consider.
- Call Quality: Call quality is subject to internet quality and server settings. Low-quality internet may cause dropped calls, echoes, or delays. However, provided with correct QoS settings and given enough bandwidth, VoIP sounds as good as or better than TDM.
- Upfront Investment: If you’d prefer desk phones and not computer screens or mobiles, there’s an initial investment for VoIP handsets. However, VoIP is significantly cheaper than TDM systems and is not mandatory; many people are successfully using softphones on their existing devices.
How to upgrade from TDM to VoIP?
Upgrading from a traditional TDM system to VoIP starts with choosing the right provider that fits your business needs. At ComparedBusiness UK, we make this easier by connecting you with reliable VoIP service providers across the UK. Just submit your business details in under 2 minutes, and we’ll get back to you with a list of reliable VoIP service providers in the UK.
