As fibre to the home (FTTH) deployments with passive optical networks (PON) continue at an ever-increasing rate, the constant growing demand for internet video streaming has fixed copper and wireless service providers already conducting trials of GPON and EPON, with plans for deployment imminent. PON is the highest speed, longest life, lowest cost, point-to-multipoint network infrastructure available on the market. Offering a genuine future‐proof access network with flexibility and upgrade capability well into the future. This high bandwidth, power saving, green technology is transforming a wide range of businesses and government agencies. Including mining accommodation camps, hotels and multi-dwelling units, campus-style building layouts, retirement villages, residential and commercial developments, corporate and high-rise buildings.
At a recent fibre conference hosted by MyBroadband, SEACOM reiterated that we have a surplus of core fibre and not enough last-mile deployments. This is in due to the fact that wireless compliments our geographic make-up, however in dense suburban areas, where the demands on capacity are more, it is more feasible to deploy a fibre network to offer capacity to numerous subscibers while keeping costs low. This is where PON falls in.
What is PON
A passive optical network (PON) is the section of a Layer 2 network that includes everything between two active elements: the headend unit, or optical line terminal (OLT) and the customer premises equipment, or optical network unit/terminal (ONU/ONT). A PON uses optical wavelength-division multiplexing (WDM) so a single fiber can be split to connect multiple ONUs to a single port and can be used for both downstream and upstream traffic to support quad-play services: data, IPTV, voice, and security.
The OLT broadcasts the same data to all ONUs/ONTs. An ONU/ONT can recognize any data specifically targeted for it by filtering data using ONU-ID. Since all active ONU/ONT upstream signals transmit at 1310 nm, a time-division multiplex (TDM) format must be used to manage and grant timeslots in which each ONU/ONT is allowed to transmit to the OLT. The OLT determines the distance and time delay of each subscriber. Then the total available bandwidth is divided between all ONUs so each user only gets a fraction. The upstream transmissions, via burst-mode operation, are allocated on an as-need basis by the OLT for each ONU/ONT that needs to send data.
GPON – Gigabit Passive Optical Networks
ITU has developed many standards of PON since its inception 10 years ago. The ITU-T standard is G.984. It delivers 2.488 Gbits/s downstream and 1.244 Gbits/s upstream. GPON uses optical wavelength division multiplexing (WDM) so a single fiber can be used for both downstream and upstream data. A laser on a wavelength of 1490 nm transmits downstream data. Upstream data transmits on a wavelength of 1310 nm. If TV is being distributed, a wavelength of 1550 nm is used.
EPON – Ethernet Optical Networks
IEEE developed another newer PON standard. Based on the Ethernet standard 802.3, EPON 802.3ah specifies a similar passive network with a range of up to 20 km. It uses WDM with the same optical frequencies as GPON and TDMA. The raw line data rate is 1.25 Gbits/s in both the downstream and upstream directions.
To summarize, WISPs are starting to use PON to provide triple-play services including TV, VoIP phone, and Internet service to subscribers. The benefit is much higher data rates that are essential to video streaming and other Internet services. The low cost of passive components means simpler systems with fewer components that fail or require maintenance. PON is growing in popularity as the demand for faster Internet service and more video rich content grows. GPON is the most popular in the U.S. whereas EPON systems are more prevalent in Asia and Europe.
Ask our team of specialized solutions experts on which PON technology you should be using for your last-mile solution.