It’s not available in your office park yet, but it’s on the way. Chinese networking and telecommunications company, Huawei, has a prototype Giga DSL system that can deliver a combined rate of 1 Gbps line speed within 100 meters of a remote terminal (RT) cabinet. It scales down to 500 Mbps if you can connect within 200 meters of the cabinet.
This follows another Huawei project called SuperMIMO that uses four twisted copper pairs to deliver 700 Mbps over 400 meters. You might recognize MIMO as the WiFi 802.3n antenna technology used to extend range using multiple antennas for both transmitter and receiver. MIMO stands for Multiple Input Multiple Output. The ideas is that radio waves bounce around and interfere with each other and themselves in an effect called multipath distortion. With more than one antenna and some intelligence in the system, you can sort out the wave patterns and recreate a clean signal.
So what does wireless transmission have to do with copper wires buried in the ground? For business telecommunications, such as multi-line telephone, T1 and Ethernet over Copper, the twisted pair lines are not installed individually. Instead, collections of them run together in binder cables with 50 pair or more. The twisted conductors cancel out most electromagnetic interference for low speed transmission, such as analog phone and dial-up Internet access. Higher speed signals, such as EoC or T1, can transfer to other pairs in the cable creating crosstalk interference. This is where MIMO can reduce that interference between wired paths in the cable just like dealing with multiple paths through the air.
Other telecom equipment vendors have been active in this field as well. Alcatel-Lucent has their own approach called DSL Phantom Mode that delivers 300 Mbps over two copper pairs. Over longer distances up to 1 km, it can deliver 100 Mbps. With 1 km spans, this system would work well for Ethernet over Copper in business districts and industrial parks.
Alcatel-Lucent’s breakthrough is something called a phantom circuit. These circuits were used in the early days of wired communications to transmit more telegraph signals or telephone calls. The principle is that two phone lines, consisting of one twisted pair each, will carry two separate telephone calls. But if you connect a circuit between them, that can be used as to carry a third telephone call or telegraph signal. Interference is eliminated by using transformers on each end of the lines and connecting the third circuit between center taps on the transformers. Since the lines are balanced, they don’t notice this third or phantom circuit riding along on the same copper.
Alcatel-Lucent also uses bonded copper pair to increase bandwidth carrying capacity and VDSL2 vectoring to cancel the cross talk between multiple lines in the same bundle. Like MIMO, vectoring employs digital signal processing to analyze the effect of interference on signals among copper pairs on a symbol by symbol basis. This is something that was out of the question before high speed DSP became affordable. By throwing enough mathematics at the signal waveforms, it is now possible to make finer and finer corrections to maximize throughput of any wired or wireless transmission system.
What’s driving such a fury of investigative work into leveraging century old copper connected to telephone company central offices? Bandwidth demand is ramping up exponentially right along with the processing and storage needs of big data. The move from local data centers to the cloud also means that faster network lines are needed for WAN as well as LAN connections. Fiber speeds are increasing, too. But fiber only reaches 75% of business locations, at most, and is expensive and time consuming to install. If existing copper can be made to meet the increasing bandwidth demand, businesses can rapidly increase their MAN and WAN network speeds using connections they have now.
Are you feeling pressed for speed on your network connections? Both copper and fiber solutions are available now that weren’t in place even a short time ago. Check Ethernet over Copper and Fiber bandwidth prices now and see what’s available for your business location.