016 Riaz Esmailzadeh. Published 2016 by John Wiley & Sons, Ltd. Companion Website: www.wiley.com/go/BTTM Broadband Telecommunications Technologies and Management Historical Note An early example of a telecommunications system is the Royal Mail of the Persian Empire circa 500 BC. The Empire ruled over the region between the Indus River (present day India/ Pakistan) and Thrace in the present day European Turkey. It also extended as far as Libya in North Africa. The Empire was divided into different 'Satraps' or provinces, which were ruled by governors appointed by the central government. To rule effectively, fast and reliable messaging between Susa the capital and provincial centres was necessary. However, the distances were prohibitively long, and the means of travel were slow. For example, the distance between Susa and Sardis, a major Empire centre in Lydia, was some 2700 km. Travelling this distance on foot would take 90 days. A faster way of travelling was by horse but the animal and the rider needed food, water and rest. A messenger travelling by horse could expect to cover perhaps 100 or SO kilometres per day, which would have been a great improvement but this still required 27 days of travelling. The Empire needed to respond to emergencies, whether local unrest or natural disasters, and clearly such long delays were not acceptable as they would greatly reduce the chances of a successful response. The Persians had constructed a network of roads and relay stations to improve travelling time. At these relay stations fresh horses and couriers were ready to receive a message and take it to the next station, thereby removing the need to rest riders and horses. The ancient Greek historian Herodotus (484-425 BC) wrote of these Persian mounted postal carriers: 'Neither snow nor rain nor heat nor gloom of night stays these couriers from the swift completion of their appointed rounds'. Interestingly, this is the unofficial motto of the US Postal Service [1]. The main Royal Highway that connected Susa and Lydia comprise