Railway communication networks need important changes

train solutionGSM Railway (commonly known as GSM-R) is an “international” Wireless communication standard for railways that allows communication in this environment. Indeed it was a system that was developed for Europe, but due to its success it has been deployed in Asia-Pacific, Middle East and Africa.

It is the network that has enabled trains and control centers to communicate with each other for well over 10 years. Similar to a standard GSM network, but the “base stations” run along the railway track (not on a traditional two dimensional system) and hence this is what allows trains and the control centers to communicate even when the trains run at over 400 km/h.

GSM-R has been so successful that forecasts say that this network still has some years of growth left, however there is one very important issue, that causes the market to think that the time has come to find an alternative. The issue is quite clear. GSM-R is a 2G network, and it is not IP based. Carriers only have a limited amount of radio spectrum allowed and they are phasing out older, less efficient 2G technologies in favor of newer systems like LTE. That, some people say, makes GSM-R virtually an outdated system that will soon become too expensive (or impossible) to run.

Is  LTE an alternative for GSM-R?

Many say that LTE is definitely a very strong contender. However, for LTE to be the adequate successor of GSM-R, certain hurdles have to be crossed. First of all, LTE will have to prove itself as being a telecommunication system that offers railway operators: Reliability, Availability, Maintainability and Safety. Without all these four requirements covered, no communication network will be taken on by the railway operators as an alternative to GSM-R.

Once LTE accomplishes reliability, availability, maintainability and safety, it will be a much better system for the railway operators, because not only will LTE be able to cover “core services”, but it will also be able to offer “additional communication services”. The latter are passenger services and business support process services. The non-core services may not be a must to operate, but they will definitely gain in importance if the railway operators want to give their passengers added value services and become more efficient from a business perspective. The railway is not alone in the transport market and they have to fight against the other modes of transport to obtain the desired market share, both in the passenger market and the transport of goods market.

For example, when a passenger selects travelling on a train or on another mode of transport, he/she will evaluate the ease with which a route can be planned (traveler information; schedules, delays, etc.) or the ease with which a ticket can be obtained (e-ticketing). Moreover the passenger will most definitely value very highly the availability of broadband internet access and on-board multimedia services.

LTE, the future of communications for transportation

Apart from this business perspective, there are obviously many specific technical issues which have to be studied in great depth. LTE will not only need to prove that it is capable of giving all the features which GSM-R offers for core services, such as Voice Group Calls, Voice Broadcast Calls, Location Addressing, Data Exchange, etc., but it will have to provide many new core services to the railway operators. However, this is totally logical and it is what is expected when a more modern technology and network is put into place.  LTE’s high performance and extended operational range argue well for its dominant role in the future.

In conclusion, what is clear, is that over time GSM-R will become a more expensive network than LTE, because by simply being 2G and not IP based, GSM-R cannot compete with LTE to offer these increasingly important expanded operational and passenger services. Indeed, Teldat has a lot to offer in the area of high performance services with LTE. We have been working on many projects across the globe. From USA to the Middle East across Asia up to New Zealand. Especially, offering passengers broadband connection to the internet, using Teldat’s Wi-Fi devices and special LTE routers for the transport sector.  Teldat offers communication equipment which is a core element of the mission-critical services of various transport projects.

Javier García Berjano: Online & Corporate marketing manager at Teldat. Javier manages the web, blog and other social media, as well as corporate marketing areas in collaboration with the different Teldat business units.  

SDN and NFV: New paradigm communication

Router cloud para oficinasDuring the past two years, a lot has been discussed about SDN/NFV technologies which promise major changes in the current communication scenarios. Many have pointed out that the current network status does not allow a quick evolution, new protocols or facilitate the implementation of new services.

We can consider the evolution of existing protocols or creating new ones that meet current needs, but introducing changes onto the network is very risky and no one wants to take these risks. The network has its shortcomings, but it works. This lack of interest in the evolution make some people say that the current Internet is ossified.

The implementation of new network services require operators to create overlays over the current IP network. These overlays (tunnels, VLAN…) are a first step towards the network virtualization.

Another problem operators are facing is that the life cycle of devices is becoming shorter as technology evolves very quickly. Hence operators are hard-pressed both from a technical and economical (CAPEX/OPEX) point of view.

SDN and NFV technologies are presented as a solution to the above problems.

What is SDN?

SDN is the acronym for Software Defined Networking. The idea behind this acronym is to manage data networks by separating the control plane from the data plane. Current networks are based on the use of black boxes (routers) in which the control plane (routing protocols, Access lists, policies,…) and the data plane (switching, routing) cannot be separated. This would require the operator to adapt the functional features of each manufacturer.

The SDN approach consists in centralizing the control plane, so that from this, the network operational logic made up by switches/routers (white boxes or bare-metal) can be established. From the central part (SDN controller) the switching/routing (Flow tables) will be implemented into the devices through protocols such as OpenFlow. The switching/routing operations are made based on the stored rules in the flow tables in the switches/routes.

Advantages of SDN

1.When the SDN software controller is placed in a centralized location. It will have a global vision of the network status and may take global decisions, allowing it to act simultaneously on all the devices’ flow tables. This is an advantage versus current dynamic routing protocols, in which any network status modification takes a finite time to spread and during which the network is in an unstable routing status.

2. Via the OpenFlow interface (southband API) the control and data planes become independent. This allows an easier integration of new devices to the network.

3.SDN allows part of the transport network for working traffic and another part of the transport network  for testing. This permits new features and services innovation. It’s an advantage of network virtualization that allows different types of traffic transportation without affecting each other.

4.Most of the SDN controllers on the market (OpendayLight, FloodLight,…) have an interface (northbound API) with Orchestration Software (OpenStack) from where the network policies are defined.

5. The SDN controller currently in production are written in Java, which reduces the slope of the learning curve.

What is NFV?

NFV is the acronym for Network Function Virtualization. The idea behind this acronym is as follows: As in a data center (DC), from orchestrators such as OpenStack, virtual machines (VM) can run when requested on any physical DC server, from which network features could work on any accessible server via IP. Virtualized Network Features/Functionalities (VNF) run within virtual machines or dockers. The set of servers on which VNFs run, make up the NFVI (NFV Infrastructure) network. These servers may be located at any point of the operator network.

Initially it is not necessary that NFV and SDN go together, even if they complement each other. In fact many of the objectives and advantages of both technologies are shared.

WAN accelerators, firewalls, security, balancers, etc are examples of VNFs i.e all applications that until now were performed through the appliances. Moreover, typical routing features such as IPsec, tunnels, dynamic routing can be added.

Advantages of NFV

There are shared NFV benefits which are obtained with SDN.

1.The necessary time to have a network feature up and running is considerably less, as a specific hardware is not essential. It is a software issue.

2.The VNFs run on off-the shell servers.

3.Reduce network “ossification” by allowing innovation and quick implementation.

4.It becomes independent from the hardware by being able to run on off-the-shell servers.

5.The network operations are simplified as they can be carried from a central point.

Scenarios for the use of SDN/NFV


Cloud is the first scenario for the use of these technologies. Through orchestrators such as OpenStack VMs are managed for computing and virtual storage operations. VMs, located on different servers, have access to a level 2 network through solutions such as Open Virtual Switch (OVS). OVS is able to look beyond the limits of a server and ensure access to VMs that run on different servers to the same virtual switch. OVS can be managed through SDN controllers such as OpenDayLight.

As with the computing VMs, VNFs can be instantiated within the DC’s limits.


The success of the cloud architecture based on orchestrators + controllers + OVS is extended to the WAN. From OpenStack it should be possible to instantiate VNFs within the NFVI servers. These servers can be located in severals parts of the operator network, for example, in the operator point of presence (PoP).

This solution leads to the vCPE concept (Virtual CPE): The network features now located in the client installations are partly shifted to the servers located in the PoP or on the cloud, depending on the latency needs of the involved protocols.

VNFs will not prevent the operators from having a network as at present in the sense of IP connectivity between all the network positions. NFVI infrastructure needs all the servers to be interconnected and accessible from the cloud.

What is Teldat’s position as far as these technologies are concerned?

SDN/NFV are a challenge for router manufacturers, as they introduce radical changes to the current network architecture. Teldat is not indifferent to this change and aims to adapt to the new scenario. The ability to run applications (VNFs) over our router has been a first step, allowing to split transmission services provided by the router from the network services implemented by applications that run within the router.

Juan Rodrigo:

WLAN: What are high density networks?

teldat wlan controllerA high density network, can be summarized as a network designed for various or many WLAN clients.

WLAN conservative planning approaches are designed to achieve a good and complete WLAN supply, and at the same time install as less access points as possible. In order to meet this goal in larger areas, usually a so-called Wireless Site Survey is carried out to ensure that wherever WLAN is required, sufficient field strength is available.


Hans-Dieter Wahl: WLAN Business Line Manager

BYOD and Telephony: integrated solutions and security

The concept of bring your own device BYOD is a growing trend for business IT. There are a variety of benefits allowing users to supply their own PC and mobile devices.

Employees can easily check e-mails, manage appointments via social networks and search the web. Many companies offer their own apps to allow access to corporate data, enterprise applications and enterprise infrastructure.

All IP trend

At the same time the All IP technology trend with its increasing convergence of voice and data allows VoIP Service Providers to support telephony with standard LAN devices as long as it supports the Session Initiation Protocol (SIP). In this case BYOD, or bring your own device, is a service that providers offer, allowing users to configure any SIP based device.

There are also free mobile apps and with costs for iOS and Android that enable calls via Wi-Fi and 3G/4G using your VoIP provider.

So what could be more obvious than using a smart phone also as a mobile phone over the wireless LAN in the office. This way some business apps offer convenient telephony with a variety of service functions such as hold, toggling, call transfer and conference calls. Wi-Fi suitable infrastructures allow a high quality of telephony with seamless handover, over the entire wireless LAN. As a further benefit many users have realized that it is possible to have incoming and outgoing business calls at any location within a building offering a good and stable Internet connection.

Where there is light there is also shadow

Many, especially larger companies, have noticed security issues caused by BYOD. However, up to a certain point, they have found a solution thanks to security strategies, using so-called mobile device management (MDM), as well as using a comprehensive data-protection.

SMEs are less experienced in dealing with private IT. Many of the small and medium-sized enterprises don’t know yet how to handle this issue.

The use of VoIP causes particularly in the business sector further serious security problems by opening up the local network for all computers on the Internet. The result is that firewalls for SIP calls have to be opened and thus the use of Internet providers throws the door wide open to attacks from the Internet.

Teldat Solutions

This is where the experience of Teldat will come into complete effect. The solutions which Teldat offer the SME segment contain not only the infrastructure to integrate BYOD devices but allow also a secure integration of telephony. The hybird systems act as local SIP proxies. Hence, SIP apps can connect locally to the hybird systems without any risk. The hybird systems act as a session border controller and connect to the VoIP provider. BYOD devices can make phone calls using their SIP provider without being accessible for the provider or from the Internet .

If you use for example a smart phone outside the company, the key issue for mobile freedom is VoVPN, Voice over Virtual Private Network. The BYOD device establishes via an online Internet connection a secure connection to the office. In our example, the smart phone with VPN and all safety standards carries out all functions as if it were registered on the wireless LAN of the office. Furthermore, the telephone app acts as a normal extension. Outgoing calls display the central phone number of the office.

Randolf Mayr:

An involved supplier: The key to successful projects in XXI century

Soluciones teldatDue to the large number of technologies, the growing enterprise specialization and the vast amount of information available, XXI century projects are characterized by a high complexity level. It’s quite common to find projects that integrate multiple technologies which are initially unrelated, along with information processing systems in a changing and geographically wide environment.

New needs for project managers

In this century, project managers need to plan and design solutions that meets the customers’ needs with tight deadlines and budgets, as well as being able to adapt to contingency planning. They play a crucial role and are forced to quickly learn and understand many radically different technologies, in addition to being able to explore the market looking for available solutions, comparing and choosing the best suited to the requirements in terms of functionality and costs.

Given the wealth of information available and the high level of specialization within several markets and technologies, the technological suppliers often become the project manager’s best allies. The involvement of an experienced supplier in each of the project areas, incorporates the specific “know-how” to each of the mentioned project sections. This ensures good project design, planning and implementation and also increases the chance of success.

Involved suppliers: the key to success

An involved supplier that understands the project as a whole, will provide information on its product, technology or services from an expert’s point of view, allowing a more robust design which will integrate more easily with the other project’s components. During the planning stage, the forecasts related to the different project phases are crucial, and an involved supplier will provide reliable information to estimate timing, increasing the probability of fulfilling the foreseen tasks.

During the implementation phase, the project’s high complexity increases the likelihood of unforeseen issues. The management of contingencies is essential and the supplier’s degree of involvement within the project is crucial at this stage. Generally, having a large supplier with standardized products and little flexibility, implies that the project manager must assume most of the initiative and contribute him/herself the possible solutions and alternatives which will allow reaching the project objectives.

However, collaborating with suppliers who are used to evaluating their clients’ projects as their own, by providing own resources and venturing on the project’s success, facilitates the management of these contingencies. The supplier, as an expert in certain project sections, has the knowledge to analyze and study the possible technical contingencies, as well as accelerating the time in which they can be carried out, by changing its components and/or providing possible alternatives. In the management planning, an involved supplier will find ways to accelerate its processes to adjust itself as much as possible to planning changes that may have been put into place.

For example, an involved manufacturer would be one that, in addition to incorporating all the processes that optimize its devices’ quality and price, also introduces services into its added value chain. These facilitate their products development and can range from guarantees and maintenance to facilitate project management, to having consulting departments and technical advice centers, to accompany their client in the project’s first stages.

Teldat, with 30 years’ experience in projects, is a flexible company that has always been able to understand their customers, getting involved as a supplier, seeing their customer success as its own. That nature has been one of the founding points of a successful company developed around its customers, that has premise not only to provide innovative and quality technology, but also the whole project support, and ultimately the necessary involvement to ensure their customers’ project success.

Francisco Guerrero: Francisco Guerrero, Telecommunications Engineer, is the Head of Teldat's Product Marketing Department.
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