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.

The Role of VSAT in Supporting NGOs during Disasters in Africa (Part 2): Zambia and Cape Verde

This is the second article of the two-part series “The Role of VSAT in Supporting NGOs during Disasters in Africa”. The first article focused on telemedicine projects in Mozambique and Uganda. This article will look at the role of VSAT during disasters in two more African countries: Zambia and Cape Verde.

Emergency telecommunications play a critical role in the immediate aftermath of disasters by ensuring the timely flow of vital information that is much needed by government agencies and other humanitarian actors involved in rescue operations and providing medical assistance to the injured. The impact of disasters is even worse for those living in remote and isolated areas with no access to basic information and communication facilities that are essential in providing the alerts so vital to saving lives.

The best emergency solution to utilize during emergencies is VSAT technology. VSAT is not affected by natural calamities like earthquakes, floods, and storms as much as terrestrial networks. This is why VSAT technology directly supports many NGOs and military operations, allowing them to cope with contingencies. Because of this, the International Telecommunications Union (ITU) considers emergency telecommunications such as VSAT to be a core element of its projects that integrate telecommunications/information and communication technologies in disaster prediction, detection and alerting.

Emergency VSAT Solutions – Saving Lives During Disasters

1) Flood in Zambia 2008

The main emergencies that occur in Zambia are very much water-related and are predictable. Every year, there are floods along the river areas, primarily the Zambezi belt. When floods occur, people are often displaced. In 2008/2009 floods, over 4,000 people were displaced along the Zambezi belt. The 2008/9 rain season peaked in January 2009 with all parts of Zambia receiving normal to above normal rainfall The heavy precipitation in the country, coupled with similar rainfall in neighboring Angola, caused flooding along the Zambezi and Kwando Rivers, which displaced over 102,000 households, damaged growing and matured crops, and caused significant threats of waterborne diseases.  The five affected provinces were the Western, North-Western, Eastern Luapula and parts of the Northern Provinces. The government undertook rapid assessments in the affected districts, detailing the immediate need of food aid, shelter, clean and safe water, and rehabilitation of infrastructure.

The International Telecommunications Union (ITU) provided VSAT satellite terminals to Zambia to assist officials in their relief efforts after severe floods affected 19 districts across the country. The floods destroyed roads and terrestrial communication links, hampering the coordination and delivery of assistance. This deployment of emergency VSAT solutions proved critical for the government and allowed humanitarian aid agencies to conduct rescue operations, medical assistance, and recovery. The VSAT mobile terminals deployed by the ITU were easily transported by road and air to the affected regions, and the VSAT terminals facilitated the coordination of relief operations by both government and humanitarian agencies to aid the victims.

2) Volcano Eruption in Cape Verde

The eruption of the Pico de Fogo volcano began on the 23rd of November, 2014 and continued until the 8th of February, 2015. By the end of the eruption, the lava had covered an era of approximately 520 hectares with an average 8-meter height lava wall. The 88 days of intense and effusive eruption culminated in the total destruction of all houses and community infrastructures of the localities of Portela and Bangaeira – Chã das Caldeiras, forcing the evacuation and displacement of 994 people. As of the 8th of December, 2014, lava had destroyed 90 buildings, including the national park headquarters, wine production facilities, a primary school and a hotel, as well as more than 429 hectares of land, resulting in great material and economic loss and leaving many without a source of income.

The International Telecommunications Union (ITU)  deployed VSAT communication equipment following the eruption of the Fogo Volcano on the 24th of November 2014, which affected most of the population of Fogo Island. The VSAT equipment was used for coordination and relief activities on the ground. The ITU deployed Iridium satellite VSAT communication terminals to support the preparedness and rescue activities.

Vizocom has an NGO Support Program, where Vizocom will provide fast and reliable communication services with exceptionally low prices to support NGOs and their causes.

The Role of VSAT in Supporting NGOs during Disasters in Africa (Part 1): Mozambique and Uganda

Natural disasters such as floods, fires, and storms affect thousands of people in Africa. From the destruction of buildings to the spread of disease, natural disasters can devastate entire countries overnight and seriously disrupt the community with massive human, material, economic and environmental losses. To prevent these losses during disasters, emergency communication systems are critical in terms of safety, and ensuring the continuous operation and rapid recovery of emergency communication systems is more important than ever.

The best emergency solution to utilize in these situations is VSAT technology. VSAT solutions act as very dependable backbones for communications during and after calamities. The inherent nature of VSAT communications via satellite and its connectivity advantages makes VSAT the ideal means of communication during emergencies.

During disasters, the first action should be to connect the affected site to multiple other sites, and this can be done quickly using VSAT. The other important tool for communication is the satellite phone , which does not rely on ground infrastructure for connectivity. Below are examples of how VSAT solutions have directly supported the NGO’s relief operations during disasters.

Emergency VSAT Solutions – Saving Lives during Disasters

1. Cyclone in Mozambique in 2008

The tropical cyclone Jokwe hit northern and central Mozambique on the 9th of March, 2008. The Category 4 cyclone had winds of up to 170 Km per hour and brought torrential rains, prompting the government to declare a Red Alert, which is the highest level issued for natural disasters. The red alert was issued for the Provinces of Nampula, Zambézia and Sofala, as well as the coastal areas of the Districts of Maganja da Costa, Pebane, Moma, Angoche, Mogovolas, Mogincual, Mossuril, and Nacala. A lesser Yellow Alert was issued in the central provinces, specifically in the districts of Inhassunge, Chinde, Marromeu, Chiringoma and Dondo. According to the Government National Institute for Disaster Management (INGC),tropical cyclone Jokwe killed 7 people, damaged around 30,000 houses, 200 schoolrooms, and dozens of health clinics, prisons and other public buildings. An estimated 41,000 hectares of maize were destroyed.

 

The Emergency Telecommunication Cluster (ETC), with support from Telecom sans Frontieres, installed VSAT equipment and provided support to INGC and the humanitarian community in each of the emergency operation centers in Caia, Mutarara, and Mopeia. Data connectivity was provided in Caia through an ETC VSAT station; in Mutarara, through the World Vision VSAT station; and in Mopeia, using UNICEF‘s BGAN portable satellite terminal. The emergency VSAT systems in place helped the NGOs conduct rapid emergency procedures. Telecom sans Frontieres also installed a BGAN and proxy-server in Caia to decrease the usage load on the VSAT at the CENOE office. Lacking outside contributions, the Emergency Telecommunication Cluster used advanced funds from UNICEF and WFP.

2. Flood in Uganda

Unusually heavy rainfall from July to November of 2007 led to flooding and water-logging across a number of districts in eastern and northern Uganda, particularly in the Districts of Soroti, Amuria, Katakwi, Bukedea, Kumi, Lira and Sironko. This gave rise to a major humanitarian response across all sectors. An estimated 20,000 households were severely affected and 58,000 people were displaced. With about 80 percent of crops destroyed by floods, food insecurity was imminent. The flooding disrupted delivery of social and economic services like education, health, trade and agriculture – which resulted in increased risk of communicable diseases especially as the floodwater receded. Malaria and diarrheal disease incidences greatly increased by over 30%. Several districts were ravaged by torrential rains and flash floods that swept through the country, destroying road and communication links, and submerging crops, which compelled the Government to declare a state of emergency.

The International Telecommunications Union (ITU) deployed 25 VSAT terminals to help restore vital communication links in the aftermath of severe floods that affected the eastern and northern regions of Uganda. With the restoration of the communication links, designated government officials and other humanitarian agencies were able to coordinate relief operations efficiently. The ITU provided bothThuraya hand-held satellite phones and Inmarsat Global Area Network (GAN)terminals. The Thuraya satellite phones used both satellite and GSM networks to accurately locate the GPS coordinates for the aid relief and rescue. The Inmarsat GAN terminals were mainly used for voice communications and high-speed data.

This article will be continued in the second part of this series titled: The Role of VSAT in Supporting NGOs during Disasters in Africa (Part 2): Zambia and Cape Verde.

Vizocom has an NGO Support Program, where Vizocom will provide fast and reliable communication services with exceptionally low prices to support NGOs and their causes.

5G – When Can You Really Expect to See Next-Gen Mobile Technology?

These days there are lots of talks about “5G”, the new Fifth Generation of mobile connectivity technology. Many of major operators such as Samsung, AT&T, Verizon, Nokia, and Huawei are working full force to make 5G happen in a tight competition.

But what exactly is 5G and when will it be in use?

What is 5G?

Until now, the only issue that can be confidently said about 5G is that obviously it is the fifth generation of mobile network technology, and it promises 4 major improvements:

1) Much Higher Speed

5G promises to provide speeds as high as 10Gbps (in theory) and as high as 100Mbps in congested networks which is multiple times higher than the current 4G platform.

2) Lower Latency

While 4G has a latency of about 30-50ms, the latency of 5G is expected to be in the range of 1ms or less.

3) Number of Connections

While 4G networks can provide up to thousands of connections, a 5G network is expected to increase that to millions of connections per square kilometer. This is especially important with regards to the expected explosive growth of IoT devices to about 20 billion devices by 2020.

4) Lower power consumption

5G is expected to consume less battery power than 4G.

Apart from the above assumptions, the actual technical details of 5G is not yet defined, and there is a fierce competition to finalize the standard, which is expected no sooner than 2018.

When will 5G become available?

The current estimates are talking about 2020 as the year when we can start using 5G. There are talks about providing limited 5G services as early as 2018 to cover the Winter Olympics in South Korea.

However, when considering all the remaining challenges that need to be resolved before 5G actually replaces the 4G infrastructure, it seems we still are a few more years away from having a widely-spread 5G network.

Some of these challenges are:

1) Defining the final standard

2) Providing the required backbone infrastructure that can handle the very high speeds that is required

3) Embedding the required hardware in all mobile cells and other mobile devices.

Conclusion

5G network is inevitable – for sure it is the required communication infrastructure for the 3rd decade of the 21st century to complement other emerging technologies such as , Artificial Intelligence (AI), and live video communications. However it seems we would need to wait for 5 more years to see a wide coverage of 5G for our daily use.

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 Point to Point Microwave Link

Wireless and microwave point to point links are widely used as a quick-to-deploy and cost effective alternative to fiber optic cabling for interconnecting the network of two sites with distances of few hundred meters and up to 50 km or more.

However like any other solution and probably more than many others, establishing a reliable and high-quality microwave point to point link can be quite challenging, and if it is not properly designed and implemented, it can cause major quality issues such as lower throughputs, link instability, and longer than expected latency.

In this article, I have tried to very briefly explain some key factors that should be considered in a proper point to point microwave link design – so that IT managers and engineers who are not experts in the field would have enough idea to enable them to properly evaluate and control such work.

What is a good point to point microwave link?

The quality of a point to point microwave link can be determined by below measurements:

1) Signal to Noise Ratio (SNR):

This ratio is measured by dB and shows the strength of signal vs the noise level for that frequency channel. The higher the value, the better but it should be at least 20 dB.

2) Bit Error Rate (BER)

This figure shows the % of bits of data with errors vs the total number of bits that have been transmitted during a period of time. The value is usually expressed as 10 to a negative power. The lower this figure, the better is the link quality. Good BER rates are usually in range of 10 -8 or better.

3) Bandwidth Throughput

This is the actual amount of data that can be transferred per second and is expressed by bits per second – for example a bandwidth throughput of 100 Mbps means about 100 megabits of data can be transferred by the link in every second. Obviously the larger this figure, the better the link.

4) Latency

Link latency determines how much time it would take to transfer the data – for a good microwave link, the latency should be fixed and not going over 2-3 ms. The easiest way to check the latency is to ping the destination device.

5) Link Availability

This parameter is expressed in % and determines for what % of time the link has been established over a certain period of time, usually in a 12 months period. A reliable microwave link should have link availability as good as 99.999%.

As microwave links can be well affected by time of day as well as many other geographical factors, for critical links it would be important to have a constant test of at least 48 hours.

5 Key Factors for a Stable Microwave Link

Below are 5 key factors you would need to ensure about for having a reliable and stable microwave link:

1) Frequency Selection

Microwave links range from 2.4GHz to 42GHz spectrum. The higher the frequency, the higher the available capacity but at the same time, the effective range is lowered and the link would be more susceptible to rain or high humidity. To use a frequency, a license should usually be obtained from the legal authorities of the country. There are also a few frequency bands that are “license-free” – mainly 2.4GHz, 5GHz and 24GHz.

While these license-free bands are in much greater use, professional solutions more depend on utilizing licensed frequencies which would guarantee a free-to-use spectrum greatly improving link reliability.

2) Calculating Capacity

The required capacity (bandwidth throughput) of a point to point microwave link is a key design parameter.

As the capacity increases, you would need to design the link for a higher SNR, resulting the need for stronger equipment and antennas.

3) Calculation of Line of Sight and Path Loss

For point to point microwave links, the antenna on the two sides should be in line of sight of each other. The line of sight can be limited by natural or man-made obstacles and also by the earth’s curvature which limits the practical distance of microwave links to 50-60kms (which would call for 100m tower heights and large dish antennas to achieve).

There are now many computer applications that can accurately predict the line of sight and path loss however a visual survey by an experienced engineer is also necessary.

4) Interference and Fading

Interference and fading is another issue that if not handled correctly, can considerably affect the link reliability.

Apart from issues such as Fresnel zone, rain fade, and multipath fading which require proper consideration during the path loss calculation, there are also other factors causing interference such as installing the radios adjacent to other radios which would greatly affect the receiving sensitivity of the radio (like when you try to hear a weak voice when standing beside a big speaker that is playing music).

5) Redundancy

The reliability of the link can be greatly increased by applying redundancy. In frequencies of 7GHz and above, dual redundant radios can be connected to the same antenna.

But this is not possible in lower frequencies and two independent radio links should be installed with sufficient frequency and space diversity.

Who can design and implement a successful point to point microwave link?

Design and implementation of a successful and reliable point to point microwave link requires good theoretical knowledge about RF design and antennas, as well as good deal of practical experience.

The concepts mentioned above are the primary information you can ask an implementer to make sure they have the required knowledge and expertise. You should also ensure you receive clear test reports for the established link.