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38
Residential PC Access: Issues with Bandwidth
Availability
Kevin C. Kahn, Intel Corporation
Abstract
The preeminent interactive information access device in the
business world today is clearly the personal computer. Via the PC,
individuals access the exploding array of information sources both
within their businesses and throughout the Internet. PCs are
rapidly penetrating the consumer environment as well, and we
strongly believe that the PC will become the center for national
information infrastructure (NII) access for the residential
consumer. The intelligence encoded in PC applications and their
improving human interfaces will make PCs the tool of choice for
ubiquitous consumer information access. However, to achieve their
great potential in this role, residential consumer PCs must have
access to adequate communication bandwidth. This bandwidth must be
priced to be attractive to the residential consumer. The consumer
must be free to access all information services using this
bandwidth.
High-bandwidth access to information services must get the same
level of attention with respect to public policy as providing
competitive television and telephone delivery systems. This
attention is needed to ensure that the bandwidth, access, and
consumer choices are made available in ways that promote the growth
of consumer NII use.
This paper develops these themes by examining the forces that
are driving corporate PC network access to the NII and the various
network topologies being discussed for the residential environment
(HFC, FTTC, etc.), as well as possible future service directions.
We then develop what we feel are the critical requirements for
bandwidth availability for residential PCs.
Statement of Problem
The personal computer has become a ubiquitous networked
communications platform within the business environment. In
addition to traditional communications applications such as
electronic mail, it is now becoming the base for all sorts of
information access and personal communications tools. These tools
enable a new level of business activity that includes everything
from World Wide Web access for general information acquisition to
various levels of electronic commerce and personal conferencing.
Key to this development of widespread, cost-effective information
and communications applications have been a number of important
technologies. First among these has been the deployment of
high-bandwidth network connections in both the local and wide
areas, utilizing high-volume components, based upon open standards.
Free and open access to this bandwidth has permitted any software
or hardware developer or information service provider to easily
enter these businesses. For example, there are numerous suppliers
of network connection hardware and software, a growing number of
competing conferencing products, and the beginning deployment of
multiple on-line news services from traditional and nontraditional
information publishers utilizing the World Wide Web. The resultant
competition and interactions are leading to rapid development of
the business use of the developing NII.
The same dynamics must be allowed to operate within the critical
residential environment to support the development of individual
utilization of the NII. While there has been a lot of focus on the
larger infrastructure developing to support the NII, particularly
in the context of the Internet, there has been less focus on the
data access issues of the ''last mile" or access network to the
residence. What discussion has occurred seems to revolve largely
around video-on-demand entertainment services and telephony. We are
concerned that while public policy may operate to guarantee
competitive entertainment services and telephony over cable or
telephony infrastructures, it might not guarantee the deployment of
the reasonable levels of openly available, discretionary
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bandwidth required to energize an affordable and comprehensive
personal computer-based information infrastructure.
The deployment of bandwidth that can be utilized in an open
manner to access NII services from the home needs to be encouraged.
For data, this access should be via general packet protocols (based
on the Internet standards of TCP/IP) that permit users direct
interaction with any service they desire. Specifically, data
services from the home should come to be viewed like existing
telephony services that allow consumers to access any services
anywhere in the nation. It may be that for other multimedia
services, such access would be better provided via circuit-oriented
services such as switched ATM virtual circuits (although promising
work is ongoing on utilizing packet protocols for this as well),
but in any case the same principles of openness and full
connectivity must apply. We also believe that the development of
industry-driven standards or implementation agreements for
attaching to and utilizing this open bandwidth will be critical to
the creation of a competitive environment for consumer information
applications. The government role should be to encourage rapid
industry convergence on such de facto standards or implementation
agreements that can later be the basis of more formal de jure ones.
This paper attempts to lay out some requirements for the
development of consumer PC information services broadly within the
NII.
Background
The Business Environment as an
Illustrative Example
As a point of reference let us first consider the typical
business access being deployed to allow PCs to utilize the
developing NII. The typical networked PC in the office is attached
to a 10-Mbps Ethernet or similar performing Token Ring network.
(International Data Corporation estimates that in 1994, 73 percent
of the business PCs in the United States were attached to local
area networks.) While this bandwidth is shared with the other users
of the network in most cases, switched networks are beginning to be
deployed that replace the shared access with dedicated access. In
addition, technologies such as 100-Mbps Ethernet are appearing that
will also greatly improve the bandwidth available to the individual
user. Beyond the local environment, most large corporations are
deploying reasonable bandwidth into the Internet at large. This
combination makes available relatively high-speed access to
information and services whether local to the business desktop or
remote.
In addition to the bandwidth that is available, another key
aspect of the business desktop is the development of standards.
Industry-driven network connection standards have driven down the
cost of connecting to the network from the PC. For example,
Ethernet controller cards for PCs now typically sell for less than
$100, operating systems increasingly come with protocol software
built in, and a growing number of applications comprehend
networking capabilities. Platform software standards have made it
possible for creative developers to build software independent of
the nature of the specific network. For example, the Winsock de
facto standard for accessing network services on the Microsoft
Windows Operating System is allowing application developers to
focus their efforts on enhancing function in their products rather
than on adapting those applications to a variety of different,
incompatible, network services.
Network protocol standards have allowed end-to-end services to
operate over a wide variety of network implementations. In
particular, general packet networks have allowed a wide variety of
data services as well as new applications such as video
conferencing to begin to operate without special provisions from
the providers of the networks. An entrepreneurial developer need
not make deals with a variety of platform and network providers to
begin to deploy an application in this environment. Neither is an
interested business consumer restricted from beginning to take
advantage of such new services by the choices offered him by
various network suppliers.
Key aspects of the business environment are that it has been
almost entirely industry driven and motivated by competition. De
facto standards or implementation agreements have been rapidly
developed and only later evolved into de jure standards. Throughout
the evolution of the business and the associated standards, the
intellectual property of the participants has been respected by the
processes. It is interesting to note that the more ponderous de
jure first approach to standards represented by the International
Telecommunications Union (the official international body for
defining standards within the telecommunications industry) has been
considerably
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less successful in affecting the U.S. environment than have the
more chaotic and rapid moving processes of private company
consortia or the Internet Engineering Task Force (the de facto
group that defines Internet standards).
A couple of other interesting aspects of packet networks are
typical in the business data environment. End systems are always
available to be connected to—that is, they are always
"online." It is thus reasonable to build applications that initiate
connection to a user's system from a service at any time. This is
different from an environment where, unless the user has initiated
a connection to the network, information cannot find its way to the
user's end system. Related to this is the fact that packet networks
inherently support multiple simultaneous connections. That is, an
end system can have an unlimited number of distinct applications
running at the same time, each of which is using some of the
physical bandwidth to connect to another distinct end system. There
is no notion of the line being busy. Again, this flexibility opens
up many possibilities for applications that operate in parallel
with each other over the same physical connection. It allows
service-initiated contact with an end system even while the user is
doing other things over his connection.
The Current Residential
Environment
We can compare this business situation to that seen in the
residential environment, first by looking narrowly at what is
really available today, and then more importantly at what is being
tested and deployed for the near future. Today's electronic service
to the home consists of a number of options.
First among these is the existing plain old telephone service
(POTS). This is universally available and provides a completely
open but relatively low bandwidth access to data services for the
consumer. Using 14.4-kbps and more recently 28.8-kbps modems, the
consumer can connect to any information service or network.
Traditional choices have been the private information services such
as CompuServe, Prodigy, or America Online. However, there are a
growing number of general Internet access providers available via
this route as well. These provide general packet access into the
Internet and thus to any information service in the developing
NII.
An improvement over POTS in terms of available bandwidth is an
integrated services digital network (ISDN) line, which potentially
provides up to 128-kbps access over a single wire. Fewer
information service or Internet access providers have thus far
deployed ISDN access, and the availability and practicality of
utilizing this level of service varies considerably around the
country. Like POTS, this is a circuit-oriented service that must be
initiated by the consumer. That is, unlike the typical business
connection, an information service usually cannot autonomously
contact a consumer's PC to provide information or service. Also,
while more flexible in some respects than POTS, ISDN is for the
most part not useable by multiple separate applications
simultaneously, thus further limiting the range of applications
that can utilize it. ISDN can be used effectively to connect an end
system to a general purpose router that provides a point of
presence for the Internet or other general purpose network. Used in
this manner, ISDN may provide our best short-term hope for general
purpose residential access. Also, since ISDN can provide fast
connections to another end system when compared with POTS, it can
approximate the speed of being always connected for certain types
of applications. While in principle POTS can also be used in this
manner, the combination of increased bandwidth and connection speed
makes ISDN much more practical in such a configuration.
In contrast to these point-to-point telephony based services,
the cable industry has focused on high-bandwidth broadcast services
for video. The cable infrastructure is typically highly asymmetric
in its bandwidth with much higher speed available into the home
than out. Currently, in fact, most cable systems have no return
path available. Also, cable is unlike the telephone where a
consumer can call anyone or access any service on any other
existing telephone system. The services provided today via the
cable infrastructure are generally chosen by the cable system
operator or according to the "must carry" rules. Cable systems are
generally closed systems that encompass everything from the content
source to the set-top box, which provides a conventional television
signal to the appliance.
There are beginning to be trials of data services over the cable
infrastructure. However, in the spirit of the existing industry,
these may tend to be for services driven and chosen by the service
provider rather than the consumer. In the case of cable TV
programming, the limited number of available channels means that
the MSO
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must select which channels to broadcast. For data services,
however, open packet access means that beyond the provision of the
data bandwidth, there is no need to limit access to content in this
manner. On the positive side, the cable infrastructure brings the
promise of relatively near-term residential broadband service.
Cable could certainly offer the advantages of high-bandwidth,
multisession, always-on data delivery. In particular, by offering
high-quality Internet access, cable could provide much of the
flexibility we desire. It is important that PC access to broadband
information services follow the telephone model rather than the
broadcast TV model of access.
Analysis, Directions in the
Residential Environment, and Forecasts
Access Network Technologies
Two major groups of companies are vying to provide digital
services to the residential environment: the existing local
exchange carriers and the cable entertainment companies. The former
are building on their expertise in operating a highly reliable
telephony network by offering higher-bandwidth services through
ISDN and through cable overlay systems that are capable of
supplying broadband residential service. The latter are leveraging
their existing investment in a physical plant oriented to deliver
many analog television channels so that they can begin to offer
digital entertainment channels and various levels of broadband data
communications to the home. As a part of this enhancement of
services they frequently wish to offer telephony services via this
network as well. This competition should be a positive force for
consumers in the long term, provided that it offers real
competitive choices to the consumer as well as to service
providers.
A number of physical architectures have emerged for deployment
by these companies. The most popular of these include the
following:
•
Hybrid fiber coas (HFC): In this scheme,
optical fiber is used to bring signals from a head end to
neighborhood nodes. At these nodes, the signals are placed on a
coax system for distribution to the residences. The cable industry
target for residences served by a single coax segment is 125,
although in early deployments the number is larger. Since the coax
is a shared medium, the homes on a single coax segment share the
available bandwidth. For most current deployments, the amount of
bandwidth available from the home (either on the cable or via a
separate POTS path) is much smaller than that available to the
home. HFC is particularly attractive as an upgrade path from
existing analog cable systems.
•
Fiber to the curb (FTTC): In this scheme,
optical fiber is used to bring signals from a head end to a
pedestal on the street that is within a relatively short distance
of a collection of served homes. At the pedestal, signals are
placed on coax or twisted pair lines to the home. While the optical
fiber bandwidth is shared (as in HFC), the drop to the individual
home is not.
•
Fiber to the home (FTTH): In this scheme,
optical fiber is deployed all the way to the home, where it is
converted as appropriate to provide digital services. At this
point, this scheme is not being pursued to our knowledge in the
United States, although it has been proposed at times in other
national markets.
•
Asynchronous digital subscriber line
(ADSL): For areas where the length of the lines from the last
point of electronics to the served homes is bounded, ADSL provides
a technique for utilizing existing telephony infrastructure to
carry higher data rates. It uses more complex signaling electronics
over existing copper to provide data rates capable of supplying
digital video.
Beyond these wired topologies, experiments are also beginning
that use wireless technologies. For example, direct PC utilizing
direct broadcast satellite technology provides an asymmetric
bandwidth connection similar to using cable combined with POTS for
a return path.
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Bandwidth and Parallelism
A common theme among all of these approaches is that the
allocation of bandwidth into the home is different from the
allocation of bandwidth out of the home. From a purely
architectural perspective this is unfortunate, since it is an
asymmetry that makes an artificial distinction between providers
(who need high outbound bandwidth) and consumers (who can get by
without high outbound bandwidth). In the full NII where
telecommuting will be common, video telephony will be widespread,
and a true cottage information industry will become an important
part of the national economy, this asymmetry will become a barrier.
However, as a practical matter for the short-to midterm, the key
will be reasonably high bandwidth into the home and moderate
bandwidth out. This arrangement will cater to information retrieval
applications where the bulk of the data flow is inbound with much
smaller flows out to make queries. Provided that the outbound
bandwidth is high enough, it can also support limited video
telephony and telecommuting applications. We and others have
demonstrated the practicality of such application at ISDN speeds
(128 kbps) via products like ProShare™ videoconferencing and
RemoteExpress™ remote LAN access. Nevertheless, higher rates
would greatly improve performance as well as support more parallel
activities.
For the long term it is critical that residential services
support a full range of simultaneous activities within the home. It
should be possible for children to be involved in remote education
activities while one parent is actively telecommuting, the other is
accessing entertainment or shopping services, and power or security
monitoring is operating in the background. Solutions that force
artificial limits on conducting such parallel activities will make
it impractical to depend upon network access as an integral part of
the home. Furthermore, each of these individual activities may
require simultaneous sessions. A child may be connected both to
school and to a library system; a telecommuter may be accessing
corporate databases while also checking travel arrangements with an
airline. A shopper may be doing comparisons on products offered by
competing providers. From a technical perspective, the solution to
these multiple access issues is either the provision of multiple
virtual circuits or a general packet network interface (or more
likely some combination of these technologies).
Openness of Access
A key to allowing these applications, even in the face of the
sorts of bandwidth available in the near-term deployments, is to
put the use of the bandwidth completely under the control of the
consumer. Consider two approaches to providing access to
information services. In the first, a cable system contracts to
make available one of the online service providers (say,
CompuServe) using some of its digital bandwidth to the home. From
the consumer's point of view a bundled package is offered that
allows direct connection to the service for some fee. The service
being provided by the cable operator is CompuServe and not generic
online access. If consumers wish to subscribe to a different
service, they cannot use the cable bandwidth to do it. Furthermore,
if a new provider wishes to enter the business and have good access
to customers, it may need to arrange business deals with many
different network service providers. The comparable situation in
the telephony industry would be that the range of people consumers
could call from home would be affected by their choice of local or
long distance carrier.
The alternate approach is typified by the existing low-bandwidth
telephony access system and the growing Internet service providers.
Here, the customer gets access to the general packet switched
network and uses that to provide common carriage of data to various
information service providers. ISDN can be used in this
configuration to provide moderate rate connection to a router from
which general Internet connectivity can be provided. Note that the
owner of the access network is not involved in the selection of the
available services. That selection is between the consumer and the
ultimate provider. Today, this access is the norm for
telephony-class access. As we move toward higher-speed access
networks, it is important that the model exist for broadband as
well. Again the comparable situation in the telephone industry is
that anyone can establish a business phone number and then
advertise directly to potential consumers for business without
further involvement of the network providers. Where cable companies
choose to provide Internet access on the cable, this fits this
model as well.
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The argument here is not that cable operators should be
precluded from offering packaged services. They should certainly be
allowed to offer them as well as local content, provided that they
also provide consumer-controlled access to competitive offerings.
Openness should exist in both directions. That is, providers should
be able to attach to access networks to offer their services to
consumers (similar to requirements for allowing video service
providers to access "video dialtones"). At the same time, consumers
should be able to attach via their access networks to providers who
have not chosen to directly connect to that access network.
Openness of Content and the
Development of New Services
We do not need to wait for the implementation of all digital
networks and the general NII to see examples of why we are
concerned with the issue of open bandwidth access. We can find
today in analog distribution systems an interesting example of how
fragile the relationship between openness of network capabilities,
content provider innovation, and application creativity can be.
This example appears in the use and distribution of material in the
vertical blanking interval (VBI) of broadcast video signals. Note
that the issues in this example are more complex than open access
to bandwidth since they deal with bandwidth ownership and contracts
between MSOs and content providers. However, the example does serve
to illustrate how subtle issues in the nature of the distribution
networks can affect the creation and deployment of new
applications.
Standard U.S. television signals must provide a period of time
in each frame to allow the electron beam that paints the screen to
move from the end of the screen back to the top in preparation for
painting the next set of lines. This period is the VBI and can be
seen as a black bar if the vertical hold of a television is
misaligned. Since this part of the signal is not used for carrying
the picture, it can be used to carry other sorts of data without
disturbing the video broadcast. The most common example of this is
closed captioning, which is carried in a part of the VBI.
As broadcasters begin to think creatively about their content
and work with application developers, other possible uses of the
VBI to enhance the broadcast material can emerge. Examples include
digital forms of the stock ticker seen on some news networks,
digital references to sources of additional information to augment
the content of a show, digital indexing information to assist in
selective viewing of the material, and undoubtedly many more.
However, any such program-enhancing use of the VBI must reach the
end consumer to be useful. While the 1992 Communications Act
required that program-related material in the VBI should be carried
by local cable operators, exactly what constitutes program related
is debatable. As a result, there is no guarantee that a content
provider who finds a creative use of the VBI to provide, in
conjunction with an application developer, an enhanced service will
actually be able to deliver that service to the consumer.
This issue can be viewed as an example of the difficulty of
defining what openness in access means, even within the existing
rather limited sorts of broadband distribution that exist today. A
service may no longer be a two-party transaction between the
provider and the end customer. It may now involve at least three
parties and become dependent upon the cooperation of the access
network provider. This substantially raises the hurdle to entering
the business with a new service, particularly one that may be of
interest to only a small percentage of consumers. Even though a
broadcast channel is already carried by the vast majority of access
network providers, it may be necessary to reengage all such network
providers to even begin to offer a service. This certainly provides
a barrier to innovation that need not be present. It is exactly
this sort of barrier that we are concerned not be erected as
digital services begin to be deployed. It must be possible for
innovation to be between the provider and the consumer over an open
digital highway. Conversely, it must also be possible for the
network service provider to benefit from the expanded use of the
network.
Openness of Equipment
Another key difference between the current directions in the
cable access networks and the existing telephony networks is
important to the rest of this discussion. This is the issue of open
equipment connectivity and ownership of customer premises equipment
(CPE). Today, the consumer owns the telephone, the TV, the PC,
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and the modem for the PC. However, it is generally the case that
the cable access provider owns and provides the set-top box.
Furthermore, the lack of standards for the physical network may
make it more difficult to find an alternative supplier of CPE. This
is quite different from the telephony world, where the access
network provider terminates his network at a demarcation point,
providing a standard form of connection to which customer-selected
and customer-owned CPE can be attached. The combination of the
ownership and the standards aspects of this arrangement have
together spawned a vigorous industry in CPE suppliers. For
telephony, the connectivity standard is the RJ-11 connector and the
set of electrical and tone signaling standards supported over it.
As a result, PC access to networks via modems can be achieved with
the same equipment, anywhere in the country.
The importance of the openness of CPE is beginning to be
understood. For example, a press release from Congressmen Bliley
and Markey issued on March 16, 1995, states,
Restricting consumers' ability to purchase and
own cable "set-top boxes"and other communicationsinterface
equipment is like putting a straight-jacket on
technologicaldevelopment.… There's noincentive for
improvement because there's no competition.… Today'sadvanced
phones only happenedbecause of a healthy, competitive retail
market—and so did therevolution in computer modems and
faxmachines that followed.
However, there is more to energizing the broadband CPE industry
than just allowing retail purchase of the set-top box. Consumers
must see an advantage in purchasing the equipment, and vendors must
see a large market to be served in order to invest in developing
products that will attract consumers. Neither of these will happen
very quickly without the development of standards for the point of
attachment of the equipment.
Consider how likely consumers would be to purchase feature-laden
phones if they could not expect those phones to work after they
moved homes. Likewise, consider how likely a company would be to
develop an innovative new phone product knowing that it could be
sold only to that set of consumers who were served by some specific
phone companies, and that the company would also have to deal with
unhappy consumers who discovered that the product ceased to work
after they changed providers. Our concern is that consumers be able
to buy PC equipment and applications that will effectively attach
anywhere in the United States to the NII, and that they be able to
freely move such equipment and applications with them.
Industry-driven discussions are under way in various industry
groups (e.g., the ATM Forum) toward the establishment of such de
facto standards or implementation agreements.
Affordability
A considerable concern exists about the affordability of an open
consumer broadband data service. Clearly, the bandwidth must be
priced at a level that will allow reasonable access to a broad
spectrum of users. True open competition should cause this to
occur, as can be seen by looking at how other uses of the bandwidth
in the access network might be priced. For example, consider a
higher-level service that has been proposed, namely video on demand
(VOD). This service promises to deliver to the consumer an online
replacement for videotapes (and eventually probably much more
interactive sorts of experiences). Assuming that one uses MPEG2 to
compress a 2-hour movie, then this service must deliver on the
order or 4 to 6 Mbps for 2 hours to the consumer at a price
competitive with what she can rent the movie for today (on the
order of $3.00). VOD is an individual service delivered to a single
consumer at a time. Thus it is reasonable to expect that
competition will drive the cost of similar downstream bandwidth of
an unrestricted sort to be similar. (Actually, the resources to
deliver the unrestricted bandwidth are less since no server is
involved.) Clearly, this accounts only for the access network
provider part of the unrestricted service, but it at least provides
a starting point. It is harder to estimate what a consumer should
be paying for upstream bandwidth, but a similar sort of analysis
for a bundled service that makes more upstream demands (perhaps
shopping or interactive gaming) should provide an estimate there as
well. We are not trying to suggest any particular price structure
for consumer-controlled bandwidth, nor are we suggesting price
regulation. Rather, we are trying to suggest that competitive
forces should cause it to be priced in a somewhat similar manner to
similar levels of bandwidth utilized for services bundled by the
local access network provider.
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An Architecture for a Long-Term
Residential NII
The actual deployment of broadband services to the residential
NII will be evolutionary from today's physical networks. Economic
and practical considerations preclude any revolutionary replacement
of access networks with some uniform and full-service digital
infrastructure. As a result of this evolutionary reality many of
the requirements we have for a long-term infrastructure cannot be
fully met in the short term. Indeed, some of the standards that we
believe will be critical to providing the full potential of the NII
are still in embryonic stages. Nevertheless, it is important to
develop a vision of where we would ideally like to wind up if we
are to generate public policies that encourage development to
proceed toward an end-point architecture that can realize all the
potentials of the NII.
We believe that the architecture should be broken into three
parts: core networks, access networks, and home networks (Figure
1). Core networks are those networks that provide generalized
connectivity both locally and across wide geographical areas. They
correspond in today's telephony infrastructure to the long-distance
carriers plus that part of the local exchange carriers'
infrastructure that carries traffic between the central offices
that serve customers. Access networks are those networks that
connect the core networks to residences. For example, the HFC
networks that are being considered for deployment to connect
regional hub systems to homes are access networks. Finally, home
networks are those that operate within the residence.
Figure 1
Elements of an architecture for realizing the full potential of a
national information infrastructure. ATM,
asynchronous transfer mode; HFC, hybrid fiber coaxial; FTTC, fiber
to the curb; FTTH, fiber to the home;
and ADSL, asynchronous digital subscriber line.
Note that any of these networks can be nonexistent in a specific
deployment. In an existing cable system using HFC to deliver only
broadcast-type services to dedicated set-top boxes in a home,
neither a core network nor a home network may exist. Likewise, one
could view the current telephony infrastructure as often not having
an access or home network, since for practical purposes it
generally appears that the CPE connects directly to the core
network.
We expect that core networks will typically be those with
symmetric bandwidth. Considering today's trends, these are likely
to be ATM-based networks. We also believe that it is in the
interest of the carriers that provide core networks to encourage
use of bandwidth by consumers. There is today competition among
core network providers in the telephony long-distance business, and
we would encourage such competition to continue into the broadband
world. Given this competition, the easy access by the consumer to
multiple core network providers, and the desire of those providers
to sell their bandwidth, we believe that the requirement of
sufficient, affordable, consumer-directed bandwidth will be met in
these networks. Furthermore, there is already much momentum in the
standards associated with communications over these networks
(ranging from TCP/IP to ATM) so that effective consumer utilization
of this bandwidth seems possible.
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Home networks are not yet at all well defined. However, as one
sees more digital information appliances deployed within the home,
the desire to interconnect them will increase, and this will give
rise to various sorts of home networks. Displaying images from
security cameras on a TV or PC, driving an interactive program on a
TV from a PC, or operating a multiplayer game across multiple TVs
or PCs in one or multiple homes are all examples of applications
that will involve a home network. Home networks are likely to be
fairly symmetric, if for no other reason than that there will
likely not be a single special "source" to drive any asymmetry.
Access networks may well remain asymmetric regarding bandwidth
due to the economics of some of the popular access network
topologies. For example, HFC will likely continue to supply much
more downstream bandwidth than upstream bandwidth for the
foreseeable future. We are most concerned about the evolution of
the access networks since they are the critical bridge between the
consumer and the core networks. While the consumer can choose what
to deploy at home, and there is already a path to active
competition in the core networks, the access networks may have much
less natural competition.
Once one understands these three related networks, it becomes
clear that the critical issue for them is to define stable
interfaces that can allow them to evolve independently while still
delivering to the consumer a high level of service. The connection
standards between the access networks and the core networks are
already getting some amount of attention via the discussion of open
video service providers. That is, this interface is the one that a
service provider will be concerned about, whether the service is a
local video store or a general long-distance carrier service. The
connection standards between the access network and the home
network have received less attention. This is the interface
discussed above in the section titled "Openness of Equipment." We
believe that it will be critical to elevate the discussion of this
interface and build policy that actively separates the home network
from the access network via appropriate standards for the reasons
discussed above. In addition to the standards, this is also the
interface across which we believe we must guarantee reasonable
consumer-directed bandwidth.
If we define effective standards at each of these points, then
it should be possible for an information industry to develop that
supplies consumers with equipment and applications that allow wide
exploitation of the NII. In our vision, consumer hardware has a
common socket for attaching to the NII. It uses common protocols
for interacting with NII services. These protocols operate in the
packetized Internet world and in the home to allow easy access to
the educational and information resources of the Internet. The
typical home has access to sufficient bandwidth to make access to
these network resources a pleasant experience. The choices of what
network services are available to the residential consumer are
essentially unbounded. The local access network provider may choose
to package and sell some services, thus making them easier to use,
but there are no roadblocks to open consumer access to the NII at
large.
The key to all of this is the existence of the interface
agreements that allow development on either side of the interface
to progress independently and that do not overly constrain the
sorts of implementations permissible between the interfaces.
Without such industry-driven standards or implementation agreements
we will be in danger of one of two extremes. On the one hand, their
lack will cause the coupling of what should be distinct parts of
the NII, thus slowing development of what should be independent
parts. On the other hand, their overspecification will stifle
creativity by admitting only a single family of products that can
operate within the NII.
With open bandwidth and protocols, intelligence can exist at the
periphery of the network as well as inside it. An innovator with a
good idea can create an information service as an end point on the
network and sell to the consumer an access tool that resides at the
consumer's system. In doing so there will not be any impediments
due to a need to negotiate business deals with various network
providers. This openness will lead to an opportunity for much
greater innovation than that possible with an architecture that
gives preference to the provision of service intelligence only
inside the networks.
Recommendations—Requirements for
Widespread PC Access
1.
Provide reasonable levels of bandwidth to and from
the home at consumer costs. Data bandwidth into the home should
probably at least mirror what is available today for the corporate
user accessing the Internet. This argues for a minimum of T1 (1.5
Mbps)-level rates to each home, and more likely, for peak levels of
at least Ethernet (10-Mbps) speeds. Obviously more is better, but
the key issue is that the consumer must be able to
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access rich multimedia content at speeds that make
the operation a pleasant one. Initially, it is acceptable that the
bandwidth from the home be less than that into it. However,
extremely low outbound bandwidth will limit the efficiency of any
interaction. Furthermore, there are certainly interesting
applications that will be enabled only by relatively high outbound
bandwidth as well (for example, work at home or video security).
Ultimately, the access network should not overly constrain who can
be the providers of services and who can be only consumers. With
the right bandwidth levels, the NII can truly energize a
grassroots, distributed economy. The first step in this direction
can come from the rapid, ubiquitous deployment of ISDN to the
residential environment. While it does not meet the full
requirements, it can quickly get us moving toward the long term and
can allow interesting applications to begin to be deployed as it is
embraced by existing service providers.
2.
Permit consumer control over the use of this
bandwidth to conduct simultaneous digital interactions with
multiple services via open packet protocols. It must be possible
for intelligence in the user's system to efficiently access
multiple services in the NII to generate value at the end system by
the combination of services. The openness of the protocols and of
the connectivity they provide is absolutely key to enabling the
development of new services and to competition among service
providers. Consumers should be able to access any service in the
NII, just as today they can access any telephone from their
residential telephones. The choice of local access provider should
not preclude this accessibility.
3.
It must be reasonable for multiple PCs and other
information appliances within a residence to be simultaneously
accessing the Internet or other broadband services. The fact that a
child is conducting an educational interaction with some service on
a PC should not preclude a parent from conducting a financial
transaction at the same time. It is desirable, in fact, that all
home information appliances be viewed as equals to that there is at
least logical symmetry between originating information inside or
outside the home for consumption inside or outside the home.
4.
Encourage sufficient standards to facilitate a
commodity consumer business on at least the national level for PC
connectivity. Competition drives costs down and service levels up.
However, meaningful competition cannot take place unless a large
marketplace becomes available to the potential suppliers. Consider
the differences in corporate networking costs today versus 15 years
ago. Standards such as Ethernet have energized an entire industry,
with the result that the cost of connectivity for an end system has
approached $100. In the consumer market segment, the standards in
place for telephone connectivity have done the same thing for
products that attach to an RJ-11 socket. This benefit will not
accrue to NII connectivity if every regional or metropolitan market
segment requires different consumer equipment for connectivity. For
example, the consumer is not served well by the multiplicity of
ISDN "standards" across the country. A resident of the United
States should be able to move NII equipment anywhere in the country
and use it effectively, just as can be done today with other
appliances. It is important to note, however, that the most
effective standards in the business world are those that have been
initially industry-driven, de facto ones that only later were
codified into a de jure form. (For example, the nearly ubiquitous
Ethernet and TCP/IP came about in this manner, while the OSI
protocols represented an attempt to drive standards from the de
jure side first.) The role of the government should not be to
impose standards but rather to create policy that facilitates the
rapid development of appropriate industrial ones.
5.
Permit consumer ownership of the periphery of the
network in terms of what kind of equipment is connected. (Of
course, this should not preclude an access network provider from
leasing equipment to the consumer as an alternative.) Similar to
the previous point, we can see an entire industry that has
innovated based on the ability of companies to develop products to
address consumer needs, without needing the permission, or worse,
the active participation of intermediaries to become successful.
Look at the innovation that has occurred since the
Carterfone decision opened up access and ownership of end
equipment for the telephone network. The evolution of capabilities
offered by the personal computer is another example of
market-driven innovation. Locking access networks into an
environment where only provider-owned or provider-sanctioned
interfaces are permitted to be attached to them recreates the old
phone network and its constrained equipment competitive
environment.
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Conclusions
It is not clear to us at this point that the natural and policy
forces at work in the emerging NII will achieve all the important
results outlined above. There is, unfortunately, something of a
chicken-and-egg problem concerning open residential use of the NII.
The emergence of innovative NII applications utilizing residential
broadband capabilities depends on the existence of those
capabilities, while justification for the deployment of those
capabilities requires hypothesizing the existence of those
applications. As a result, we have a situation where to some extent
policy choices may need to precede market development. We do not
suggest a move toward a highly regulated environment, since
ultimately that is completely counterproductive to the development
of a new industry. However, we do suggest that policymakers need to
find ways to encourage the development of an eventual architecture
that supports the full potential of the NII.
To some extent this notion is already present in the types of
trade-offs being made to balance the cable industry's and telephony
industry's developing competition in each other's businesses. We
are simply encouraging policymakers to take a broader view of this
set of problems that looks beyond this level of competition to
include the rest of the infrastructure that the consumer will need
to become a full citizen on the NII. Policymakers should see that
more is involved than allowing content providers open access to
consumers or considering what the competitive trade-offs should be
between allowing cable systems to offer dialtone and telephone
companies to offer video. They also need to look at the provision
of general data services from the perspective of the consumer. We
believe that more attention should be given to the provision of
open, standardized, commodity-priced network access to the NII at
large. We believe that only with this capability can we tap the
PC's full potential to become the consumer's interactive access
point to NII services and bring to the residential consumer the
dynamics that have so dramatically benefited the corporate PC
user.
Representative terms from entire chapter:
access networks
