Cabling for the future

Even in the era of smartphones, WLAN and Internet of Things (IoT), LAN cabling remains the backbone of all networking in ICT. But like the structure of a building, cabling too has to be planned with foresight, providing headroom for future loads. It has to be designed to allow several generations of active devices to be connected.

Analysis published by Gartner and other market researchers highlights the importance of cabling. Research shows that more than half of all network interruptions are caused by the physical layer. Frequent causes include products that are of poor quality, are not reliable or are not used correctly. Convert this into numbers and you get the following: cabling material represents just 3.5% of the costs of an IT set-up, but it is responsible for more than 50% of operational reliability. Using the wrong cabling or cabling that is not powerful enough is, therefore, one of the most expensive mistakes to make.

10G requirements are increasing in all areas. Here are a few examples:

• Data throughput: When a large number of computer workstations access virtual machines, cloud services, collaboration platforms, voice over IP, software as a service and video streaming at the same time, IP traffic increases to a level never experienced before. The LAN requires enough capacity to allow for productive working with low latency.
• Wireless everywhere: Mobile communication is ubiquitous and requires high bandwidth. More and more additional Wi-Fi access points are having to be connected in buildings and on campuses. The smartphone and tablet density of a radio cell is constantly increasing, as is applications’ need for bandwidth. The aggregate data volume of a WLAN cell is therefore continuously rising.
• All over IP: Offices, buildings and factories are increasingly becoming intelligent. More and more systems and functions, also those in remote places, are being connected and integrated in central building management systems. This task could nicely be taken care of with IP, Ethernet and LAN. Alongside data transfer, the LAN is increasingly being tasked with providing IP-based end devices with energy using Power over Ethernet (PoE).
   

In conclusion, LAN has to be designed for more demanding tasks. Old office networks with 1GbE, poor-quality connectivity or shoddily installed cabling will fail in the scenarios described above.

The market has recognised this at the right time. Standards, product developments and market statistics are all pointing in one direction. The next logical step is 10 GbE. The standardisation committees have prepared the change of generation to Cat. 6A/Class EA and 10GBase-T early on. R&M adapted the LAN range to the 10G era at an early stage. Now demand is increasing for top-flight solutions for using 10G in offices and buildings. In the financial year 2017, the share of Cat. 6A reached the 50% mark of all sales of copper products for the first time. 10G is going to be the leading technology. It ensures that a LAN will be able to support the applications and scenarios that are currently discernible for longer than the typical lifespan of the cabling.

Additional challenges

New demands will lead to additional cabling-related challenges. When higher bandwidths, remote power supplies, consolidation and digitalisation are introduced, the underlying conditions will change dramatically.

First example: 10GBase-T reacts very sensitively to external noise. It is around one hundred times more sensitive in terms of electromagnetic disturbances from outside than today’s widely used 1000Base-T. Cabling standards will have to be adhered to 100% for 10GBase-T to work; there is no concealed headroom. But further effects which so far have not been covered by the standards will also become important. R&M investigates these effects and develops cabling systems which ensure 10G compatibility and also meet the standards requirements. But IEEE development never stops. 10GBase-T is used as the basic technology for further transmission protocols.

One of these protocols, 25GBase-T, could be the long-awaited next evolution step in the LAN sector. With a maximum transmission distance of 30 m, 40GBase-T is more suitable for data centre infrastructures. With 25GBase-T, the transmission distance should be considerably higher. The expected range of 50 m would be sufficient for many typical LAN environments and cover around 70% of the links installed today.

The 2.5- and 5GBase-T protocols only extend the lifespan of existing cabling to support broadband WLAN in compliance with IEEE 802.11ac. The next generation of wireless access points requires 10GBase-T.

RJ45 stays

The new category 8.1, specified for transmission frequencies up to 2000 MHz, is recommended as a connection solution for 40- and 25GBase-T. The tried and tested RJ45 format is to be retained. The standards TIA 568-C.2 Cat. 8 and ISO/IEC 11801 Ed. 3 have been approved and the manufacturers of measuring instruments have already developed appropriate devices. But as yet there are no Cat. 8.1 products available commercially for the permanent link (as at: Q1 2018). R&M also has a Cat. 8.1 solution ready to be implemented and will be launching it as soon as the technical conditions for 25GBase-T are clear.

The heat is on

PoE could become a key technology for the IoT as it delivers both energy supply and data. The third generation of Power over Ethernet (PoE) is waiting in the wings. It uses all four twisted pairs (4PPoE) and will support output of up to 90 W with currents of 1 amp per twisted pair. With 4PPoE an even greater number of devices, sensors, antennas, cameras, controllers and LED light sources can be operated via LAN cost-effectively while saving energy.

To date, PoE peak loads have often only lasted a short time, eg, during start-up or switching operations. Some new applications, however, require electrical power around the clock, eg, smart lighting and digital signage. But to date, LANs are often not specifically designed to cope with such permanent loads. The risks in planning, installation and operating the network must not be disregarded. 4PPoE takes cables, contacts and ports to their technical limits.

The cables and cable bundles heat up in continuous PoE operation as a result of the electrical resistance. If the heat cannot escape from large cable bundles, the temperature can rise greatly and the cable attenuation can increase inadmissibly. This problem can be controlled by choosing cable with a greater wire diameter, by adapting planning accordingly to specify shorter link lengths and by altering the way cable is laid in smaller bundles. The PoE Calculator tool from R&M can help in this.

Other PoE risks include:

– If connectors are unmated under load, the contacts involved are subject to spark erosion. The higher the current, the greater the damage. With an ideal contact design, the contact and sparking point are physically separate and the contact quality is thus safeguarded.

– In piercing technology, which is widely used to terminate wires in patch cords, the connection between the wire and the plug contact can deteriorate so much due to ageing that the connector self-destructs due to overheating when transmitting power. The insulation displacement contact (IDC) used by R&M excludes such risks. The company supplies patch cords with IDC technology.

In order to ensure reliable 4PPoE transmission, proper planning, selection of appropriate products and professional installation are essential. The PowerSafe seal from R&M indicates products that are particularly suitable for reliable transmission of permanently high currents in the LAN.

Infrastructure

Cabling is no longer just about connecting the work areas. Ethernet/IP services should provide connectivity throughout the building. ISO/IEC 11801-6 and EN50173-6 describe a cabling structure that fulfils these requirements. It is routed additionally and separately from the work area connections, but ideally planned and installed at the same time.

Large areas and spaces can efficiently be split into zones using a honeycomb structure. Service outlets (SO) form the centre of these zones and serve as connection points for the IP-supported devices. The radius of the zones is normally based on the coverage or range of WLAN access points. It is normally between 8 and 12 m, but may need to be reduced further for future use. SOs are ideal for connecting WLAN, LED lights and other building automation applications. Every application requires a port at the SO to ensure the connection to the floor distributor. According to use, the cabling should be equipped for 10G (Next Generation WLAN). As more and more applications are connected to the SO, the number of ports at the SO has to be further increased or network switches have to be introduced into the zone to multiply the number of ports. R&M has developed appropriate solutions for both cases. The ceiling is often seen as the best place for service outlets. This is why the concept is also referred to as ‘Digital Ceiling’. The growing number of ports in the zone increases the complexity of the cabling within the zones and thus requires more expert knowledge. R&M can provide help in the practical implementation of the Digital Ceiling with the concept of pre-installed zone cabling.

More and more optic cables are finding their way into the office floors. R&M has created ready-to-install solutions. Fibre to the Office (FTTO) and Passive Optical LAN (POL) provide large bandwidth at an attractive price.

The last meters, however, require specific cabling solutions. Microswitches or optical network terminals (ONT) connect the FO backbone and the copper connections of the IT devices. POL requires just one singlemode fibre per workstation. It thus replaces four to eight twisted-pair copper cables in floor cabling. However, all connection points are developed from the beginning. Active ports thus remain unused, something which has to be taken into consideration during planning. The R&M product range facilitates the installation of tailor-made and robust variants of the optical network termination.

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