A flexibility boost for Ethernet

By: Shajan George, Technical Director at R&M India

The boom in mobile devices has been a driving force behind the refinement of local data networks in offices, non-residential buildings, and public facilities. A stable Internet connectivity with improved performance is very essential to meet the needs of the growing number of smartphones and tables. The new generation of IEEE 802.11ac Access Points with gigabit data rates in the 5 GHz frequency spectrum will deliver better performance. However, they place high demands on cabling and data rates. However they do face challenges as structured cabling requires increased agility to deal with the rising number of surveillance cameras, security systems, building sensors and operating terminals. In addition, devices operated via Power over Ethernet (PoE) are becoming increasingly popular as a way to eliminate the need for additional low-voltage cabling. Many of these new applications require more than 1 Gigabit Ethernet. In the medium term, the only solution will be to equip local data networks to deal with 10 GbE/10GBASE-T and to use Class EA / Cat. 6A copper cabling. This will be the only way to implement the necessary system resources for high end radio networks.

However, in the short term, the market can make do with flexible, temporary solutions for its Ethernet requirements. For instance, the service life of the widely used Cat. 5e and Cat. 6 cabling can be extended even for demanding WiFi solutions. It makes perfect economic sense to pursue this course of action. As is well known, old cabling cannot be replaced as quickly as device technology is developing.

Temporary solution

The temporary solution is to operate the LAN with 2.5 or 5 gigabit/s. The industry has already agreed to these higher data rates, and the standardization body IEEE 802.3bz is working on the specifications. Experts want to scale down 10GBASE-T technology so that Cat. 5e and Cat. 6 cabling can transmit higher bandwidths. They hope to find a modulation method for 2.5 gigabit/s that works in the 100 MHz bandwidth specified for Cat. 5e, while ensuring compliance with the 250 MHz bandwidth specified for Cat. 6 in the case of 5 gigabit/s.

Check the old installation

The problem is that many old Cat. 5e/ Cat. 6 installations may not be equipped to deal with future interference. Alien crosstalk can have an impact on unshielded (UTP) cabling in particular. In the past, the alien crosstalk factor was not taken into account or measured during installation. This was largely unnecessary for physical reasons and was not stipulated by any of the standards. As a responsible and quality-driven manufacturer of cabling technology, R&M recommends the following: before upgrading from 1 GbE to 2.5 or 5 Gigabit Ethernet, the installation must be inspected and recertified. The relevant parameters can be found in the standard IEEE 802.3bz. It would certainly be unwise nowadays to plan a new installation with Cat. 5e or Cat. 6 cabling, as the industry is moving towards 2.5 or 5 gigabits in the long term. This would be a bad investment, as the latest generation of WiFi is already calling such a concept into question. Today's new installations should be planned at Cat. 6A level. With correct installation of this type of cabling, we can expect Ethernet technology to continued developing dynamically. These cabling offers reserves for the 2.5 and 5 gigabit era as well as for the future widespread use of 10 Gigabit Ethernet. The introduction of 25 and 40 Gigabit Ethernet is already on the horizon and investment in higher categories is advisable here too – in this case, planners will already have to start looking at Cat. 8 and Cat. 8.1.

Power over Ethernet (PoE) requires good planning

The development of Power over Ethernet (PoE) is directly linked to the trends described above. PoE provides an efficient and cost-effective way of supplying energy to the increasing number of powerful WLAN antennas. In future, displays, thin clients, and even room lighting may also be able to be powered via the data network. In order to achieve this, PoE output will have to increase to almost 100 watts. The impact of cable heating on data transmission performance must not be over looked. Whether existing installations are compatible with the higher PoE output and have an adequate loss budget depends on the cable and the associated planning. Shielded cables and larger conductor cross-sections generate less heat and are therefore better suited to 4PPoE. The size of the cable bundle and the installation environment also play a significant role. If high currents are present, the quality of the plug connection is also important – the aim here is to minimize the effects of sparking. R&M has developed a PoE calculator to help planners, installers and users to evaluate and check their starting conditions.