EPON vs. GPON—Which Will Be More Popular?

With the development of passive optical networking (PON) technology, two PON standards are striking in FTTH solution area and they are Ethernet passive optical networking (EPON) and ATM (asynchronous transfer mode)-based Gigabit passive optical networking (GPON). During these years, it has become a hot topic that which will be more popular in broadband access and optical telecom applications, EPON or GPON? This article will compare these two technologies from the differences of architecture, bandwidth, efficiency, cost, etc.

Architecture

The biggest difference between the two technologies shows in architecture. EPON employs a single Layers 2 network that uses IP to carry data, voice, and video. While GPON provides three Layer 2 networks: ATM for voice, Ethernet for data, and proprietary encapsulation for voice.

EPON provides seamless connectivity for any type of IP-based or other "packetized" "communications". Since Ethernet devices are so popular and easy to get, implementation of EPONs can be highly cost-effective.

In GPON, virtual circuits are provisioned for different kinds of services sent from a central office primarily to business end users. This kind of transport provides high-quality service, but includes significant overhead because virtual circuits should be provisioned for each type of service. GPON equipment requires multiple protocol conversions, segmentation and reassembly (SAR), virtual channel (VC) termination and point-to-point protocol (PPP).

Bandwidth

EPON delivers symmetrical bandwidth of 1 Gbit/s. EPON's Gigabit Ethernet service actually constitutes 1 Gbit/s of bandwidth for data and 250 Mbit/s of bandwidth for encoding. GPON promises 1.25-Gbit/s or 2.5-Gbit/s downstream, and upstream bandwidths scalable from 155 Mbit/s to 2.5 Gbit/s. GPON's 1.25-Gbit service specifies a usable bandwidth of 1.25 Gbit/s, with no requirement for encoding. Gigabit Ethernet interfaces to the aggregation switch, central office, and metro are currently cost-effective to aggregate 1-Gbit ports for transport. But for 1.25 Gbit, there is no way.

Efficiency

Efficiency has to be considered in both directions of a PON. Each PON protocol introduces its own overhead in either direction. In the downstream direction, protocol overhead could be negligible. In the upstream direction, the total scheduling overhead within EPON is from 90.33 percent to 97.08 percent compared to a GbE point-to-point link. In the downstream direction, EPON efficiency reaches from 97.13 percent to 98.92 percent of the efficiency of a point-to-point 1GbE link, while GPON in GTC Encapsulation Method (GEM) mode can achieve ~ 95 percent efficiency of its usable bandwidth. The downstream EPON data rate can be doubled to 2.5Gbps comparable to GPON.

Cost

EPON simplifies the networks and needs no complex and expensive ATM and Sonet elements. Thus it helps lower the costs to subscribers. Now the cost of EPON equipment is about 10 percent of the costs of GPON equipment.

Encryption

Encryption is part of the ITU standard. EPON uses an AES-based mechanism, which is supported by multiple silicon vendors and deployed in the field. And EPON encryption is both downstream and upstream. However, GPON encryption is downstream only.

Ethernet Features

EPON is an IEEE Ethernet standard and uses Ethernet switches within its silicon, it can natively support all of the 802.1 and 802.3 Ethernet, including VLAN tags, prioritization, OAM, etc. All Ethernet services can be natively delivered in a manner identical to what is done with switched Ethernet today. As to GPON, it only defines the transport of Ethernet frames. So it has no native Ethernet functionality. Ethernet switches must be placed either in front of or within GPON OLTs and ONTs to provide any additional Ethernet capabilities.

EPON and GPON technologies have been introduced into the market because of service quality and price point. By comparing the differences of the two technologies, it shows EPON is a superior technology for delivering residential and small-to-medium enterprise Ethernet services in terms of its advantages in bandwidth, efficiency, cost, encryption and Ethernet features. So EPON will be employed in FTTH solution area in a large scale earlier and faster than GPON.

Originally published at http://www.streetarticles.com/internet-and-businesses-online/epon-vs-gponwhich-will-be-more-popular

Why Does FTTH Develop So Rapidly?

FTTH (Fiber to the Home) is a form of fiber optic communication delivery in which the optical fiber reached the end users home or office space from the local exchange (service provider). FTTH was first introduced in 1999 and Japan was the first country to launch a major FTTH program. Now the deployment of FTTH is increasing rapidly. There are more than 100 million consumers use direct fiber optic connections worldwide. Why does FTTH develop so rapidly?

FTTH is a reliable and efficient technology which holds many advantages such as high bandwidth, low cost, fast speed and so on. This is why it is so popular with people and develops so rapidly. Now, let’s take a look at its advantages in the following.

• The most important benefit to FTTH is that it delivers high bandwidth and is a reliable and efficient technology. In a network, bandwidth is the ability to carry information. The more bandwidth, the more information can be carried in a given amount of time. Experts from FTTH Council say that FTTH is the only technology to meet consumers’ high bandwidth demands.
• Even though FTTH can provide the greatly enhanced bandwidth, the cost is not very high. According to the FTTH Council, cable companies spent $84 billion to pass almost 100 million households a decade ago with lower bandwidth and lower reliability. But it costs much less in today’s dollars to wire these households with FTTH technology.
• FTTH can provide faster connection speeds and larger carrying capacity than twisted pair conductors. For example, a single copper pair conductor can only carry six phone calls, while a single fiber pair can carry more than 2.5 million phone calls simultaneously. More and more companies from different business areas are installing it in thousands of locations all over the world.
• FTTH is also the only technology that can handle the futuristic internet uses when 3D “holographic” high-definition television and games (products already in use in industry, and on the drawing boards at big consumer electronics firms) will be in everyday use in households around the world. Think 20 to 30 Gigabits per second in a decade. No current technologies can reach this purpose.
• The FTTH broadband connection will bring about the creation of new products as they open new possibilities for data transmission rate. Just as some items that now may seem very common were not even on the drawing board 5 or 10 years ago, such as mobile video, iPods, HDTV, telemedicine, remote pet monitoring and thousands of other products. FTTH broadband connections will inspire new products and services and could open entire new sectors in the business world, experts at the FTTH Council say.
• FTTH broadband connections will also allow consumers to “bundle” their communications services. For example, a consumer could receive telephone, video, audio, television and just about any other kind of digital data stream using a simple FTTH broadband connection. This arrangement would more cost-effective and simpler than receiving those services via different lines.

As the demand for broadband capacity continues to grow, it’s likely governments and private developers will do more to bring FTTH broadband connections to more homes. According to a report, Asian countries tend to outpace the rest of the world in FTTH market penetration. Because governments of Asia Pacific countries have made FTTH broadband connections an important strategic consideration in building their infrastructure. South Korea, one of Asian countries, is a world leader with more than 31 percent of its households boasting FTTH broadband connections. Other countries like Japan, the United States, and some western countries are also building their FTTH broadband connections network largely. It’s an inevitable trend that FTTH will continue to grow worldwide.

Originally published at www.china-cable-suppliers.com