Wireless LAN coverage is nowadays mandatory for more and more customers. Meanwhile, WLAN Site Surveys is not only used for office communication like e-mail or web traffic. By now storekeepers use for instance for bar code scanners with integrated WLAN to register their stock or even the whole storage is fully automated by robots with integrated WLAN modules. In these cases good coverage and roaming without a session time out is a must.
The new generation of centralized management tools for wireless networks has arrived. We analyze Teldat´s Colibri
Humanity spends a huge percentage of its time searching for models. We search for models of the atmosphere to anticipate weather conditions, we search for models of human behavior to determine voting intentions or to predict market trends. We even search for models in the shape of share charts to setup the pricing for buying or selling stocks, but …Can the world be modelled?
With the deployment of fiber to the home (FTTH), telecommunications operators put their main focus on the residential market. This is logical, since it is where there is volume and where a small increase or decrease in revenue per subscriber is converted into outstanding results on their financial accounts.
As with almost any other access technology, once the number of households with the possibility to receive the service is steadily increasing and the network is stable and running, many operators also choose to use this deployment to offer their services to the business market.
PON (passive optical network) technologies, that enable the deployment of FTTH networks in a cost-effective manner for the residential market, are evolving at a high speed. Not only as far as protocols and standards are concerned, which are constantly enabling further increases in speed, but also at “chip” level, since it manages to implement the mentioned protocols and standards in forever smaller and more efficient integrated circuits.
Until now, to offer GPON services, currently one of the most used PON variants, the service provider had to typically install three devices at the customer’s home: (1) the “optical modem”, known in the “official” terminology as ONT, (2) the IP access router, which allows the connection of multiple devices and also typically includes a Wi-Fi access point, and optionally (3) Set-Top-Box or video decoder, if television services (IPTV) are required.
In the majority of cases, the ONT and the access router are really two different devices, when they could be only one device, as is the case with ADSL routers, which include internally an ADSL modem. Apart for using one modem in MTU (multi-user) topologies, in which several routers “hang” from one “optical modem”, this lack of integration is a sign of the lack of technological / GPON service maturity, compared for example with the mentioned ADSL technology.
An “internal type” reason for this separation between the ONT and router is due to the organizational structure within the telecom operators, whereby the ONT is considered as equipment that belongs to the operator’s own network, but located at the customer’s home, while the router is considered as customer’s network equipment and therefore managed by different departments within the operator. However, the end customer does not care and the only thing that he/she sees, is that for a FTTH service, the operator has put two boxes when the ADSL service only requires one box.
ONT GPON devices in SFP format: Convincing solution
The technological advances mentioned above are allowing the emergence of ONT devices with a SFP format (Small Form-factor Pugglable), which are normally used for other more simple optical transceivers. The SFP format allows you to provide communication equipment with fiber interfaces in a modular way, so that in a common “chassis” you can insert or connect different types of fiber. So far using the SFP ONT format devices had been residual, due to the inherent complexity of GPON and the impossibility of implementing all the necessary processing capacity into the small size of the SFP connector. It had reached the SFP ONT device market, but with a special mechanical format “backpack type”, which has consumption and heating problems.
However a new generation of chips, which have a very small size and low power consumption, is making possible the emergence of GPON ONT devices in a standard SFP format. Now the question is whether the operators will be able to organize themselves internally to transfer to the customer the advantages of a much more convenient deployment. This will indicate whether the GPON technology is “maturing”.
At Teldat we hope that this does occur, since we think that the SFP format for a GPON ONT is a very attractive and convenient solution for the end customer, since it means a lower cost, lower consumption and the reduction or integrating of devices.
GSM 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.
During 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.