Tag: Wifi

TETRA Radios vs GSM and Wi-Fi – What is the Correct Choice?

Today, different wireless communications technologies such as GSM and Wi-Fi are expanding and improving at unbelievable speeds, and it would be valid to raise doubts on the future of TETRA technology. This is especially important when we acknowledge the increasing trend of the global unification of different standards that has caused technologies such as WiMAX to be simply taken out of competition.

What is TETRA technology?

TETRA (TErrestrial Trunked RAdio) is a set of standards developed by the European Telecommunications Standardization Institute (ETSI) that describes a common mobile radio communications infrastructure. It is the next-generation replacement of the old analog mobile and handheld radios used by public services as well as many industries such as construction or oil and gas.

Unlike its analog ancestors, TETRA was built over long years of research as a digital standard to collectively provide the features of older technologies such as mobile radio, cellular telephones, pagers, and wireless data.

TETRA networks are now implemented in well over 100 countries in Europe, Middle East, and Asia.

Benefits of TETRA technology vs Analog Radios

The benefits of TETRA technology when compared to preexisted analog radios are enormous:

  1. All communications are digital and encrypted.
  2. All modes of one-to-one, one-to-many and many-to-many communications are available.
  3. Data transfer on the same network is possible
  4. Calls can be seamlessly “relayed” between the mobile stations enabling communications over very broad geographical areas.

TETRA technology vs GSM

It is obvious that the growth of cellular phone networks such as GSM have limited the TETRA market in many ways. Unlike before, where many private companies were highly dependent on using analog emergency radios for their communications, mobile phones have obviously taken over this market, limiting the usage of TETRA radios to mainly the public and emergency services.

The reasons that the public and emergency services still depend on TETRA technology are:

  1. Instant and easy one-to-many calls which is critical for emergency situations
  2. The much lower frequency used (380MHz vs 800/900MHz) gives longer range, which in turn permits very high levels of geographic coverage
  3. In the absence of a network, mobile radios can use ‘direct mode’ to share channels directly (walkie-talkie mode)
  4. Encrypted communications

TETRA technology vs Wi-Fi

Most of benefits mentioned above are also valid for a Wi-Fi based network, however due to much higher frequency of a Wi-Fi network (2.4 or 5 GHz), the very short range of a few hundred feet makes Wi-Fi not an option to consider for public and emergency services.

Future of TETRA Technology

While I predict TETRA radios will still be widely used in public and emergency services around the world for years from now due to the benefits listed above, and considering the enormous investments made in building up the TETRA infrastructures, I would predict no future for the technology in the long run.

The future of communication infrastructure is clearly in the expansion of a unified data infrastructure based on GSM technology and software based solutions.

TETRA radios only support a maximum data rate of 3.5kbps and need huge budgets for both setup and maintaining the infrastructure. It would not take much long before we see similar ruggedized, easy-to-use handheld radios that provide identical functionalities of current TETRA radios and much more, but operating on dual Wi-Fi and GSM infrastructure and at a fraction of the costs. Intelligent drones can also act as quick range extenders for cases of emergencies or natural disasters.

The question is not if this will happen, but only how many years (or maybe months) from now it will happen.

What is WiMAX and How Does it Differ from WiFi?

When speaking about wireless networks, you might have heard the term WiMAX increasingly used as a technology that will replace WiFi. If you are curious on what the differences between these two are, then this article is meant to exactly answer your questions.

WiMAX stands for “Worldwide Interoperability for Microwave Access” and is a standard-based technology for providing a wireless alternative to cable and DSL connections.

This however is also one of the usages of WiFi. Although WiFi wireless devices are mainly used for short-range wireless connection of end user devices such as laptops, tablets and smartphones, they are also used for site-to-site interconnections.

Before I explain the core difference of the two, let’s first take a look at the table below which gives some of the basic differences between the two wireless standards:

Specifications WiMAX WiFi
IEEE Standard 802.16x 802.11x
Versions of standard 802.16a, 802.16d and 802.16e 802.11b, 802.11g, 802.11n
Official Release 1997 2004
Frequency bands supported 2.5,3.5 and 5.8GHz supported 2.4 GHz and 5 GHz supported
Data rate 30-40Mbps, but lately updated to 1Gbps 54Mbps, but lately up to 1.2Gbps
Channel Bandwidth Flexible (1.25 to 20 MHz) 10 or 20 or 40 MHz
Normal Ranges 30+ Km 100m for end-user devices (up to 5Km for outdoor point to point connections)

What is the main technical benefit of WiMAX?

WiMAX is not a replacement technology to WiFi – instead, while WiFi is the de-facto global standard for wireless interconnection of end-user devices, WiMAX has addressed a specific technical deficiency of WiFi for interconnection of multiple sites.

The main drawback of WiFi technology for a point-to-multipoint connection is that it is a connectionless type of protocol named CSMA/CA (Carrier sense multiple access with collision avoidance). Without going into deep technical details, this means that as in WiFi networks all the devices of the network share the same frequency channel, to prevent collision in data transmissions, each device “listens” to make sure no other device is transmitting and then it transmits its data. I.e. there is no centralized management in the network. While this makes the network setup very simple and straightforward (which is a benefit for end-user devices), it creates major problems in larger networks especially when the distances are increased.

scheduling algorithm. Unlike a WiFi network, in WiMAX you should define and setup each subscriber station (SS) on the base station including specifying what bandwidth each SS should be given. By doing this, the base station knows the exact number of subscriber stations and allocates a time slot (access slot) to each. This protocol synchronizes the transmission of data between all the stations on the network and totally eliminates the collision issues of a WiFi network. This enables efficient and reliable connection of as many as 80 subscribers on a WiMAX network with guaranteed QoS (Quality of Service), while on an outdoor WiFi network, adding more than 10 CPEs would cause great deficiency with unpredictable quality of service.

To give an example, WiFi is like a crossroad with no traffic light where cars need to check and make sure no-one else is crossing before moving on, while WiMAX is when you have a traffic police (the base station) giving turn to each car to pass.

Conclusion

While WiFi is and will be widely used for short-range wireless connection of end-user devices, WiMAX is the correct, efficient wireless solution for long-range connection of multiple sites such as providing internet connection to multiple homes or interconnection of multiple buildings in a large compound.

5 Key Factors in Designing a Wireless Network for your Business

Wireless networks have become an integral part of any business environment these days, especially due to the increased prominence of all kinds of wireless devices such as laptops, tablets, and smartphones. Wireless networks are now ubiquitous because they provide the expected convenience, portability, and flexibility demanded by any serious business today. Another reason you see such an increase in demand for setup of wireless networks in business environments is due to the fact that a wireless network is now much faster and more reliable than before.

In this article, I will try to briefly explain some key factors that any business person who wants to set up or request a wireless network should be familiar with. It greatly helps to professionally communicate with your team and the company you contract to setup your wireless network.

What do we mean by “Wireless”?

The term wireless is of course a very broad and general term and can be applied to any device or technology that works without wires! Wireless communications include GSM, WIMAX, satellite, radio, microwave, Bluetooth, and many other means of communications.

However when we are talking about wireless network for computers, we are loosely using the term to refer to “WiFi” or the IEEE 802.11 standard. This is the common wireless (WiFi) connection you have on your laptops, tablets, and smartphones.

5 Key factors of a Wireless Network

Below are 5 key factors you would need to ensure about in any wireless network that is setup you’re your business:

1) Indoor / Outdoor Access Points

Regardless of the brand, the wireless access points are divided to indoor and outdoor devices. Indoor access points are not weatherproof but cost less and are installed on wall or ceiling of offices.

Outdoor access points on the other hand are designed to withstand outdoor climates and are usually used to cover the outside premises of your office or compound.

There are however cases where outdoor access points are used to provide coverage for indoor use – this is when you have disbursed, separate prefab caravans or trailers or tents (like oil rigs or man camps) where providing coverage for inside these rooms more efficient by utilizing outdoor access points.

2)  Number of Access Points
Determining the correct number of required access points and their proper positioning to provide proper coverage is probably the most critical step that determines the success of a wireless network.

There are many factors for determining the required number of access points, but the two main ones are:

a. You need to make sure you have all locations within the range of the wireless access point.

b. You need to make sure you have enough access points in crowded areas (one per every 20-30 users).

3) Access Point Bandwidth/Speed

The speed and bandwidth offered by wireless access points is increasing year by year at an incredible speed. While the speed of access points was in range of 11 to a maximum of 54Mbps back in 2000’s (IEEE 802.11 a/b/g standards), now thanks to the advent of many new technologies such as MIMO, the common standard is IEEE 802.11ac which provides speeds as high as 780Mbps. New standards are expected as early as 2017 to support speeds up to 100Gbps! If you are planning to setup your wireless network this year, you should go for the 802.11ac standard or newer.

4) Access Point Frequency Spectrum/Band

Older access points tended to support 2.4GHz band. The new 802.11ac standard also supports 5GHz band, enabling higher bandwidth and speed.

5) WLAN Controller

While for a very small office a standalone access point might be sufficient, in larger premises where you have to setup multiple access points, a WLAN controller would become quite critical.

The WLAN controller enables management of multiple access points, not only simplifying the management of all the access points from a single control point, but also to enable the seamless roaming of wireless devices on the move. Some manufacturers now provide software services as an alternative to hardware WLAN controllers which would provide a very attractive and cost effective alternative for SMBs.

Who can design and implement a successful wireless network?

Whether you want to test the wireless knowledge of your in-house team or the capabilities of a potential contractor, the above information will give an idea of some of the key concepts any wireless implementer should be well aware of.

The successful design of a wireless network is much more than that of course. Unless if you simply need 1-2 access points to provide coverage for a small office, make sure for larger networks you do get a professional to do it for you.