Editing Last mile (telecommunications) (section)

====Telephone====
In the late 20th century, improvements in the use of existing copper telephone lines increased their capabilities if maximum line length is controlled. With support for higher transmission bandwidth and improved modulation, these [[digital subscriber line]] schemes have increased capability 20-50 times as compared to the previous [[voiceband]] systems. These methods are not based on altering the fundamental physical properties and limitations of the medium, which, apart from the introduction of [[twisted pair]]s, are no different today than when the first telephone exchange was opened in 1877 by the Bell Telephone Company.<ref name="nxtbook">{{cite web|url=http://www.nxtbook.com/nxtbooks/natoa/journal_2009spring/index.php#/14|title=NATOA Journal - Spring 2009}}</ref>

The history and long life of copper-based communications infrastructure is both a testament to the ability to derive new value from simple concepts through technological innovation&nbsp;– and a warning that copper communications infrastructure is beginning to offer [[diminishing returns]] for continued investment.<ref name="nxtbook" /> However one of the largest costs associated with maintaining an ageing copper infrastructure is that of truck roll<ref>{{Cite news|url=https://multi-link.net/how-much-does-a-service-truck-roll-cost-your-company/|title=How much does a service "truck roll" cost your company? • Multi-Link Inc.|date=2015-04-16|work=Multi-Link Inc|access-date=2017-05-23|language=en-US}}</ref> - sending engineers to physically test, repair, replace and provide new copper connections, and this cost is particularly prevalent in providing rural broadband service over copper.<ref>{{Cite web|url=http://www.ispreview.co.uk/index.php/2016/05/aaisp-struggles-cost-keeping-uk-rural-broadband-alive.html|title=UK ISPs Struggle with the Cost of Keeping 20CN Rural Broadband Alive - ISPreview UK|last=Jackson|first=Mark|website=www.ispreview.co.uk|date=25 May 2016 |access-date=2017-05-23}}</ref> New technologies such as G.Fast and VDSL2 offer viable high speed solutions to rural broadband provision over existing copper. In light of this many companies have developed automated cross connects (cabinet based automated distribution frames) to eliminate the uncertainty and cost associated with maintaining broadband services over existing copper, these systems usually incorporate some form of automated switching and some include test functionality allowing an ISP representative to complete operations previously requiring a site visit (truck roll) from the central office via a web interface.<ref>{{Citation|last=UTEL (United Technologists Europe Limited)|title=RoboCab - Full cabinet automation (Auto PCP / AMDF)|date=2017-03-03|url=https://www.youtube.com/watch?v=klHZG4ybmxU |archive-url=https://ghostarchive.org/varchive/youtube/20211212/klHZG4ybmxU| archive-date=2021-12-12 |url-status=live|access-date=2017-05-23}}{{cbignore}}</ref> In many countries the last mile link which connects landline business telephone customers to the local [[telephone exchange]] is often an [[ISDN30]] which can carry 30 simultaneous telephone calls.