bradhall
Banned
Last mile fiber access, aka FTTx, got its foot in the door thanks in large part to growing consumer interest in broadband Internet access and competing service providers wanting to turn the triple-play bundle of voice, video and high-speed Internet services into a home run for the bottom line. IDC forecasts the market for fiber access equipment to grow from $503 million in 2003 to $2.4 billion by 2008, a 37% compounded annual growth rate.
In a just released report by Render, Vanderslice & Associates, they forecast that over one million North American homes are expected to have fiber access by the end of 2004 as the technology's acceptance continues an upward growth trend.
While the market clearly appears to be supporting the delivery of triple-play services, the big issue facing the market and still up for grabs is what FTTx technology will dominate to deliver voice, video and high-speed Internet access.
FTTx is delivered using active Ethernet and various passive optical network (PON) technologies. The passive FTTx approach utilizes equipment that does not require power, and splits or divides the bandwidth between users. Equipment used in an active Ethernet FTTx solution, which has a number of advantages over passive approaches, requires power but does not split bandwidth between users.
Here is an overview of FTTx options:
APON - BPON
Standardized by the ITU in 1998, ATM Passive Optical Network (APON) uses ATM for transport. Broadband PON (BPON) is similar to APON, with additional overlay capabilities for broadband services like video. BPON's ITU approval spec. is G.983x.
Both APON and BPON, the technology of choice for RBOCs, support data rates up to 622 Mbps downstream and up to 155Mbps upstream. This bandwidth, however, is shared between end users. Consequently, with a maximum of 32 end users per optical splitter, each end user is limited to roughly 19 Mbps downstream and less than 5 Mbps upstream.
GPON
Gigabit PON (GPON) uses a different, faster approach (up to 2.5 Gbps in current products) that encapsulates traffic in a version of the SONET-compatible Generic Framing Protocol (GFP). GPON is on track to becoming an ITU standard (part of G.984x has already been approved).
EPON
Ethernet PON, which, as its name indicates, is a technique that uses Ethernet as the main transmission method over a passive optical network runs at gigabit rates. EPON has its own standardization process underway at the IEEE.
Active Ethernet
The active Ethernet FTTx solution utilizes equipment that requires power and it delivers service over a point-to-point connection that does not split bandwidth between users. Consequently, it generally delivers higher bandwidth to end users regardless of how many broadband subscribers there are in a neighborhood. Active Ethernet runs at gigabits rates, and is based on established standards. The most common and the vast majority of all telecommunication networks are based on active components that connect end-users with their service provider's Central Office (CO). Active components are any device (CPE, repeater, relay, switch, etc.) that requires power to operate and is involved in processing information that is sent to and from various network elements.
Typical active Ethernet network architecture
Ethernet FTTX Taking Hold
According to the November Render, Vanderslice & Associates (RVA) report, Ethernet technologies currently represent about half the market in terms of homes passed. Moreover, IDC in a May 2004 report looking at the global fiber access equipment market over the next five years forecasts that Ethernet will be by far the dominant technology, not APON or the related BPON G.983 ITU standard.
Although RBOCs appear to be committed to APON or BPON, the benefits of an active Ethernet FTTx solution has definitely enabled it to stake a claim in the marketplace and is something that telcos, if they are not already looking at, might want to consider.
Active vs. Passive
Active Ethernet fiber solutions offer several major advantages that do not exist in passive FTTx technologies such as APON and BPON.
Standards
Although PON technologies are based on standards, different implementations by equipment manufacturers result in situations in which equipment from different vendors will not interoperate. As a result, generally only one vendor's equipment can be used in a passive FTTx deployment.
Active Ethernet FTTx solutions, on the other hand, support the IEEE Ethernet standard, which allows interoperability between different vendors' equipment without any need for adjustments or interoperability tests. As Ethernet does not involve any proprietary technology, equipment used in Active Ethernet solutions can be added and �mixed-and- matched' from various manufacturers.
Cost
Because Ethernet is standards-based and is used universally, the cost of Ethernet-based products and components are decreasing rapidly, putting the cost in line with passive FTTx components.
Bandwidth
In active Ethernet, each subscriber is connected by a dedicated fiber to the Ethernet aggregation switch, assuring committed bandwidth that is not shared between users. Active Ethernet solutions deployed today deliver 100 Mbps, 1 Gbps or as much as 10 Gbps to each end-user.
In an active Ethernet solution, the amount of bandwidth available to each end user stays constant regardless of the number of subscribers. Also, because less equipment is required to scale an Active Ethernet solution to accommodate new subscribers, it is much easier and more cost-effective to add new subscribers than in the case of passive solutions.
In a passive solution, whether it is Ethernet or some other transport technology, bandwidth is shared between 16 to 32 end-users per optical splitter and usually requires an additional overlay network to deliver video. In addition, when the number of subscribers in a neighborhood grows beyond either the 16 or 32 end users supported by a splitter, new infrastructure must be deployed that is likely to include laying more fiber, additional equipment and equipment upgrades. This makes the cost of adding additional subscribers greater than the cost to add subscribers in an active Ethernet solution.
In addition, as new subscribers are added in a PON solution, the bandwidth available to each user, particularly at peak usage times, is reduced because total bandwidth is split or shared between users. Consequently, the average bandwidth that each subscriber will get in a PON network is far lower than that available with active solutions.
All IP Network
Unlike a passive approach, traffic running over an Active Ethernet FTTx solution is pure IP, which greatly simplifies design, deployment, management and maintenance issues. No protocol conversion is required, and network management of all network elements as well as billing and authentication is simplified with the ability to use off-the-shelf products that are based on the same technology.
Business and Residential Offering
Active Ethernet solutions allow service providers to more easily offer different levels of service, such as different bandwidth availability for businesses and residential customers. It also enables them to combine different FTTx solutions such as Fiber-to-the-curb with VDSL over copper wire to the home; and Fiber-To-The-Business (FTTB) in which fiber is run all the way to the business office, and permits the delivery of higher bandwidth services to the business end-user. In this manner, the service provider can better manage infrastructure deployment costs and more easily differentiate between business and residential service than is possible with a passive solution.
Pay as You Grow and Network Flexibility
PON architectures are extremely limiting in the sense that network change is complicated. Optical splitters that serve between 16-32 end-users have to be deployed in neighborhoods whether there is just 1 subscriber or 32. As the infrastructure is laid for all the planned customers, the initial investment in them is high.
If growth exceeds or is lower than the intended design of a PON network, subscribers pay the price � they either have insufficient bandwidth or the cost per subscriber becomes very high.
Active Ethernet, on the other hand is scalable - components can be added as the network and subscriber penetration increases without changing the network design.
Triple-Play Ready
Active Ethernet networks have standards-based mechanisms to support voice, video and data services that assures the service characteristics and quality of service. For example, it supports video related standards like IGMP, which is the protocol that governs the management of multicast groups in a TCP/IP network, and voice and data quality of service standards like 802.1p, which provides priority to voice over data, as well as other policy enforcement and quality of service mechanisms. While providing triple play with PON networks is possible, it is not as integral a part of PON technology as it is in an active Ethernet solution. Nor is the control and management of a PON network as straight forward as in active Ethernet.
While reliability of an active solution has been perceived to be low in comparison to passive solutions, field deployments of active Ethernet solutions have proven that its reliability is very high. Different mechanisms established in Ethernet technology ensure that the overall network availability will be as high as PON networks. For example, when there is a fiber cut or equipment failure when using a ring topology, Spanning Tree Protocol (STP) and its enhanced variants (MSTP, RSTP, etc.) ensure carrier-class network reliability by re-routing traffic so quickly that data, video and voice services are not affected and is transparent to end-users.
In a just released report by Render, Vanderslice & Associates, they forecast that over one million North American homes are expected to have fiber access by the end of 2004 as the technology's acceptance continues an upward growth trend.
While the market clearly appears to be supporting the delivery of triple-play services, the big issue facing the market and still up for grabs is what FTTx technology will dominate to deliver voice, video and high-speed Internet access.
FTTx is delivered using active Ethernet and various passive optical network (PON) technologies. The passive FTTx approach utilizes equipment that does not require power, and splits or divides the bandwidth between users. Equipment used in an active Ethernet FTTx solution, which has a number of advantages over passive approaches, requires power but does not split bandwidth between users.
Here is an overview of FTTx options:
APON - BPON
Standardized by the ITU in 1998, ATM Passive Optical Network (APON) uses ATM for transport. Broadband PON (BPON) is similar to APON, with additional overlay capabilities for broadband services like video. BPON's ITU approval spec. is G.983x.
Both APON and BPON, the technology of choice for RBOCs, support data rates up to 622 Mbps downstream and up to 155Mbps upstream. This bandwidth, however, is shared between end users. Consequently, with a maximum of 32 end users per optical splitter, each end user is limited to roughly 19 Mbps downstream and less than 5 Mbps upstream.
GPON
Gigabit PON (GPON) uses a different, faster approach (up to 2.5 Gbps in current products) that encapsulates traffic in a version of the SONET-compatible Generic Framing Protocol (GFP). GPON is on track to becoming an ITU standard (part of G.984x has already been approved).
EPON
Ethernet PON, which, as its name indicates, is a technique that uses Ethernet as the main transmission method over a passive optical network runs at gigabit rates. EPON has its own standardization process underway at the IEEE.
Active Ethernet
The active Ethernet FTTx solution utilizes equipment that requires power and it delivers service over a point-to-point connection that does not split bandwidth between users. Consequently, it generally delivers higher bandwidth to end users regardless of how many broadband subscribers there are in a neighborhood. Active Ethernet runs at gigabits rates, and is based on established standards. The most common and the vast majority of all telecommunication networks are based on active components that connect end-users with their service provider's Central Office (CO). Active components are any device (CPE, repeater, relay, switch, etc.) that requires power to operate and is involved in processing information that is sent to and from various network elements.
Typical active Ethernet network architecture
Ethernet FTTX Taking Hold
According to the November Render, Vanderslice & Associates (RVA) report, Ethernet technologies currently represent about half the market in terms of homes passed. Moreover, IDC in a May 2004 report looking at the global fiber access equipment market over the next five years forecasts that Ethernet will be by far the dominant technology, not APON or the related BPON G.983 ITU standard.
Although RBOCs appear to be committed to APON or BPON, the benefits of an active Ethernet FTTx solution has definitely enabled it to stake a claim in the marketplace and is something that telcos, if they are not already looking at, might want to consider.
Active vs. Passive
Active Ethernet fiber solutions offer several major advantages that do not exist in passive FTTx technologies such as APON and BPON.
Standards
Although PON technologies are based on standards, different implementations by equipment manufacturers result in situations in which equipment from different vendors will not interoperate. As a result, generally only one vendor's equipment can be used in a passive FTTx deployment.
Active Ethernet FTTx solutions, on the other hand, support the IEEE Ethernet standard, which allows interoperability between different vendors' equipment without any need for adjustments or interoperability tests. As Ethernet does not involve any proprietary technology, equipment used in Active Ethernet solutions can be added and �mixed-and- matched' from various manufacturers.
Cost
Because Ethernet is standards-based and is used universally, the cost of Ethernet-based products and components are decreasing rapidly, putting the cost in line with passive FTTx components.
Bandwidth
In active Ethernet, each subscriber is connected by a dedicated fiber to the Ethernet aggregation switch, assuring committed bandwidth that is not shared between users. Active Ethernet solutions deployed today deliver 100 Mbps, 1 Gbps or as much as 10 Gbps to each end-user.
In an active Ethernet solution, the amount of bandwidth available to each end user stays constant regardless of the number of subscribers. Also, because less equipment is required to scale an Active Ethernet solution to accommodate new subscribers, it is much easier and more cost-effective to add new subscribers than in the case of passive solutions.
In a passive solution, whether it is Ethernet or some other transport technology, bandwidth is shared between 16 to 32 end-users per optical splitter and usually requires an additional overlay network to deliver video. In addition, when the number of subscribers in a neighborhood grows beyond either the 16 or 32 end users supported by a splitter, new infrastructure must be deployed that is likely to include laying more fiber, additional equipment and equipment upgrades. This makes the cost of adding additional subscribers greater than the cost to add subscribers in an active Ethernet solution.
In addition, as new subscribers are added in a PON solution, the bandwidth available to each user, particularly at peak usage times, is reduced because total bandwidth is split or shared between users. Consequently, the average bandwidth that each subscriber will get in a PON network is far lower than that available with active solutions.
All IP Network
Unlike a passive approach, traffic running over an Active Ethernet FTTx solution is pure IP, which greatly simplifies design, deployment, management and maintenance issues. No protocol conversion is required, and network management of all network elements as well as billing and authentication is simplified with the ability to use off-the-shelf products that are based on the same technology.
Business and Residential Offering
Active Ethernet solutions allow service providers to more easily offer different levels of service, such as different bandwidth availability for businesses and residential customers. It also enables them to combine different FTTx solutions such as Fiber-to-the-curb with VDSL over copper wire to the home; and Fiber-To-The-Business (FTTB) in which fiber is run all the way to the business office, and permits the delivery of higher bandwidth services to the business end-user. In this manner, the service provider can better manage infrastructure deployment costs and more easily differentiate between business and residential service than is possible with a passive solution.
Pay as You Grow and Network Flexibility
PON architectures are extremely limiting in the sense that network change is complicated. Optical splitters that serve between 16-32 end-users have to be deployed in neighborhoods whether there is just 1 subscriber or 32. As the infrastructure is laid for all the planned customers, the initial investment in them is high.
If growth exceeds or is lower than the intended design of a PON network, subscribers pay the price � they either have insufficient bandwidth or the cost per subscriber becomes very high.
Active Ethernet, on the other hand is scalable - components can be added as the network and subscriber penetration increases without changing the network design.
Triple-Play Ready
Active Ethernet networks have standards-based mechanisms to support voice, video and data services that assures the service characteristics and quality of service. For example, it supports video related standards like IGMP, which is the protocol that governs the management of multicast groups in a TCP/IP network, and voice and data quality of service standards like 802.1p, which provides priority to voice over data, as well as other policy enforcement and quality of service mechanisms. While providing triple play with PON networks is possible, it is not as integral a part of PON technology as it is in an active Ethernet solution. Nor is the control and management of a PON network as straight forward as in active Ethernet.
While reliability of an active solution has been perceived to be low in comparison to passive solutions, field deployments of active Ethernet solutions have proven that its reliability is very high. Different mechanisms established in Ethernet technology ensure that the overall network availability will be as high as PON networks. For example, when there is a fiber cut or equipment failure when using a ring topology, Spanning Tree Protocol (STP) and its enhanced variants (MSTP, RSTP, etc.) ensure carrier-class network reliability by re-routing traffic so quickly that data, video and voice services are not affected and is transparent to end-users.
