This paper discusses possible applications of intelligent agent
technologies in broadband networks. It begins by describing the
networks of primary interest, continues with a discussion of a
number of applications and makes a brief summary of some key agent
characteristics and capabilities. It is concluded that agents
have a multitude of useful purposes in such networks and that
there exists a rich spectrum of applications to which they can
be applied. However, to be utilized in any broadly practical sense,
various aspects of agent technologies will need adequate standardization
to ensure inter-working and compatibility. For an overview of
the FIPA perspective on agent applications, the reader is referred
to the FIPA Application Types document.
Practical broadband networks are of several general topologies and have varied physical plant characteristics. Any intelligent agents that will be active on these networks must be both network-aware and network-independent. Network independence is required so that an agent with specific functions may be deployed such that the appropriate subset of its functions for that network may be invoked transparently. At the same time, certain agent functions must have knowledge of the underlying network to perform some of their functions. Several popular broadband network architectures are briefly described below to provide the backdrop for discussion of agent applications in such networks.
Hybrid Fiber Coax or HFC networks use fiber-optic cable from the source origination point (master studio, video-serving office) to regional distribution points (headend, central office). Typically, the fiber-based distribution is then continued from the distribution point (which may serve a metropolitan area) to hubs which serve "neighborhood" areas of perhaps 400 to 2000 subscribers. From the hub, coaxial cable is run over the last several kilometers to the user typically supplying upwards of 3.1 Gbps total data rate after accounting for error correction.
Some HFC plants have activated reverse paths, which in some cases provide significant bandwidth (~1.5 Mbps) from the home to the network. Where reverse paths are not available within the HFC plant itself, a telephone return is often used. This approach generally employs low-speed modems and dial-up capabilities. The total bandwidth supported on the plant is usually from 500 MHz to 750 MHz in North America and extends to 860 MHz in some cases in Europe. Total bandwidths of 1 GHz exist, but are comparatively rare.
Most HFC plants in existence today are used for analog CATV transmissions, but a move is underway now to expand the types of information carried over them. In particular, digital video/audio and Internet applications are beginning to appear as commercial services.
The combination of advanced multimedia services with the large
downstream capacity and reverse path capability, will provide
numerous opportunities for agent-based technologies to add value
in HFC network.
Fiber-to-the-Curb (FTTC) networks extend the reach of the fiber
optic cable closer to the home than in HFC networks. In FTTC,
the fiber is usually terminated in a node which serves about 8-32
homes and is located within a few hundred meters of those homes.
The remaining run to the home may be coaxial cable, or traditional
copper telephony lines. FTTC plants are capable of large total
bandwidth (measured in Gbps) in both the downstream and reverse
directions.
Satellite networks used for commercial services today typically operate within many frequency ranges and provide an astonishing array of services.
One of the earliest commercial uses of satellite broadcasting was the distribution of entertainment programming to receive sites at the headends of CATV systems. The CATV systems then re-distribute the signal over (usually) terrestrial cable plants to consumer homes. While initially analog-based, such systems are quickly migrating to digital video compression to expand program offerings and make more efficient use of existing transponder capacity. These systems often include a facility to transmit control data thus enabling on-line delivery of entitlements and conditional access data.
DBS systems typically use high- or medium-powered transponders to transmit entertainment and data programming to users who have satellite integrated receiver-decoders (IRDs) on the ground. Anyone under the "footprint" of the satellite's broadcast may receive the signal. This footprint often covers an entire continental land mass or more. Some examples of this type of service are BSkyB in the U.K. and Primestar and DirecTv in the USA. The advent of digital video compression has expanded the channel capacity of such services many-fold compared to analog-only delivery.
Very small aperture terminal (VSAT) networks take advantage of the availability of powerful satellites world-wide. Having data rates around 2 Mbps, these networks may be considered to just qualify as "broadband" for the purposes of our usage here. Continuing advances will increase this limit in the future. Using a satellite and a powerful central hub terminal allows users of the network to avoid expensive dedicated lines to connect terrestrial networks, and to use small, relatively inexpensive antenna terminals on the user's premises. VSATs are useful because the satellite coverage area allows multicasting over a broad area; this means that businesses do not need to re-negotiate for services from each geographical provider, and many earth stations may share a common path through one satellite.
Many VSAT systems use DAMA (Demand Assigned Multiple Access) technology, in which the central control system responds to user requests for satellite resources by making a temporary frequency or time bandwidth assignment. Using DAMA technology, these systems provides efficient use of the satellite resource, allowing multiple users to benefit from lower satellite usage costs. DAMA technology allows such systems to provide a cost-efficient telephony network, because of the random and occasional nature of voice traffic.
DAMA system functions include:
Some companies operate private video networks to service their own business communications needs. These include such diverse applications as sports program delivery, automobile dealer training, medical information exchange, and internal corporate news and information updates. These systems typically do not maintain full-time use of even a single satellite transponder and thus are scheduled or demand-based.
Orbiting satellites at low or intermediate altitudes are creating
exciting new possibilities in the fields of earth imagery, global
communications and space exploration. Some of the applications
that can be accomplished with communications and tracking systems
(low earth orbiting to deep space exploration) are remote sensing,
tracking and telemetry and intelligent transportation programs.
As a transmission means for analog video/audio signals, Multi-point Multi-frequency Distribution Systems (MMDS) enjoyed only little popularity in CATV applications. With the advent of high-quality video and audio compression techniques, such as MPEG-2, these wireless systems are beginning to be exploited as an alternative to terrestrial (wired) plant. While lacking a robust reverse path, some of these systems will utilize dial-up telephone lines for home-to-network transactions. The home terminal will be similar to those used in DBS applications and will typically feature a graphical user interface and sophisticated remote control.
Whereas, in analog-only implementation these networks could deliver
perhaps 20-35 channels of programming, with compression that offering
can easily quadruple or more. Network equipment include the microwave
transmitters, MPEG-2 multiplexers (and perhaps, encoders), digital
servers and possibly telephone-path processors.
The remainder of this paper will address a sampling of applications
on broadband networks that can benefit from Intelligent Agent
approaches and briefly discuss some of the key agent characteristics,
capabilities and features needed to satisfy the requirements of
these applications.
Whether the delivery mechanism be satellite, wireless or wired, the user of the network service will have a communications terminal to make the connection to the physical plant and interpret various layers of network protocols. The terminal also usually provides the interface to the user for input and display. Some applications that may be useful on such terminals are discussed below.
The digital, compressed services emerging on both satellite and terrestrial networks present the user with a bewildering choice of programming and data. Whereas, in the past, simple "channel surfing" was sufficient to make a selection of what programming to watch, finding the desired material on today's broadband networks requires more guidance. An application called a "navigator" may be employed to meet this requirement. The navigator must be aware of the content of the network and also be able to translate user requests into the appropriate network parameters needed to obtain the selection. This would include not only frequency mapping but also mapping of "virtual" channels within a carrier such as those found in MPEG-2 Transport Streams or ATM networks.
Further, the user typically has little use for knowledge of the underlying network and rather would prefer a presentation of the available content which organizes it along practical lines:
Communication terminal agents should be capable of learning user preferences for programming, scheduling, user interface characteristics and then interpret new programming information to select that which would likely appeal to the user.
In two-way interactive networks numerous possibilities exist for on-line shopping services. These can be browser-based with direct user interaction or could be agent-based with no or little direct interaction on the part of the user. Ideally, a user could instruct an agent to locate and purchase goods and/or services meeting specific criteria of cost, availability, size, color, warranty guarantee, etc. After searching and possibly negotiating with other shopping agents, the communications terminal agent could either inform the user of the recommended choices or in an autonomous mode make the purchase for the user with pre-authorized funding. Such agents could also be constructed to monitor for discounts and special offers and purchase the product only after a pre-set selling price is met.
Undoubtedly, even simple home communications terminals will have at least basic E-mail capability. Once this attains widespread acceptance and usage in commercial applications, it will be more important than ever to assist the user in wading through the vast sea of legitimate and "junk" mail they will receive over broadband networks. Senders of such mail may also want to supply users with "category filters" that favor a certain type of message or demographic profile. Agent implementations in this area can go beyond simple filtering however, by monitoring what the user reads, saves or discards and making selections from the incoming stream accordingly.
The home or business communications terminal does or likely will
have connectivity to standard computer and entertainment peripherals.
In some applications, the terminal agent could perform useful
services for the peripherals such as monitoring for new versions
of a software program or driver at certain server addresses and
automatically downloading and installing new versions as they
become available. Peripherals with less intelligence such as VCRs
or DVD-Rs could be automatically activated to record when material
of interest to the user becomes available on the network. Such
an agent might also provide the interface to an on-line "help
and troubleshooting" agent to configure new peripherals and
perform preventive maintenance.
3.6 Customized Learning
The vast resources of the Internet provide a fertile ground for
information gathering and educational pursuits. Indeed, the WWW
was first conceived to provide a convenient means for scientific
researchers to share information. But it is already clear that
search engines alone will not provide an efficient means to extract
the knowledge bases required for the purposes of planned academic
programs. Agents with suitable intelligence could be used to synthesize
significant databases from the Internet to provide the most current
information in various programs of study. This would require the
ability, it should be noted, to judge the accuracy and sources
of the information as well as that of searching and reporting.
Operators of broadband networks can also benefit from agent technologies. In fact, the operation of a broadband network in which 24x7 availability and high quality of service (QoS) is critical is a most natural application of such systems. The laborious and tedious task of network status monitoring and corrective response to fault conditions can be readily handled by intelligent agents.
One of the fundamental tasks of a network management system is to monitor and track device alarms and report such alarms to the network operator. Current standard agents typically can discover and report on alarms, but do so simply by gathering and relaying information about the alarms to the operator, sometimes causing a flood of seemingly unrelated indications. In many cases, multiple alarms may all be related to one root cause and thus clearing the root alarm condition can also clear the subtending alarms. In any case, agent technologies could be applied to analyze such multi-alarm situations, and by using expert knowledge, correlate the individual alarms and identify the common fault condition.
If an agent can successfully analyze a complex set of cascaded alarms, it might also be possible to enable it to take action to clear the root-cause condition, thus also clearing the subtending alarms. Building the capability for autonomous action into a network management agent could have exceptionally positive effects on network availability, QoS and efficiency.
Likewise, agents could be constructed to constantly monitor network conditions and devices and take actions to prevent impending fault conditions.
Since many varieties of broadband networks may be inter-connected
to form larger networks, interpretation and regulation of QoS
at network boundaries and real-time protocol conversion and bandwidth
metering could be tasks assigned to intelligent agents on the
borders and points of presence of the network.
The advent of interactive, two-way broadband networks provides the foundation for a vast array of electronic commerce applications. Basically, almost anything that is today transacted at a physical point-of-sale, such as a market, store or shopping mall can be performed electronically over a network (as long as there is an appropriate fulfillment channel/method available).
As discussed in section 3, agents may be utilized for shopping for goods and services over the network. Agent technology could be used to give all users the capability to be sellers as well as buyers. By performing "marketing" and "sales" functions, agents hosted on a home PC or communications terminal, could turn a hobby into a cash flow stream or conduct the world's largest rummage sale. The agents could also arrange for courier fulfillment of any orders and take care of funds transfers.
The substitution of electronic value conveyed over digital bit streams for currency and coins is an exciting possibility of the digital age. The equivalent of cash may be also stored in the non-volatile memory of a certain class of secure processors. Banks benefit from the elimination of coin/currency handling and the consumer receives the convenience of chip-card portability and in some cases re-usability. While simple E-cash transactions will require a high level of security, they will not require the presence of a particularly intelligent agent. However, once broader acceptance of this technology occurs and with improvement in chip-card functionality, it can be predicted that agents to seek for the best currency exchange rates, favorable bank account interest rates, best price for specific goods, bartering agents and the like will find application in this field.
The foundation for secure credit-card based transactions is only now being pursued. An example is the SET (Secure Electronic Transactions) protocol being developed by some of the major (VISA or MASTERCARD) credit card services. Future E-commerce agents may be developed to not only execute such protocols but also to locate in real-time the most favorable credit-granting institutions and accounts and apply for such accounts and balance transfers on behalf of the user. Such agents could also produce lists of merchants that accept a specific form of credit payment for the next vacation trip the user is planning to take and suggest venues to visit based on loyalty programs associated with the credit service.
Agents to perform travel arrangement services will likely be an early use of such technology in broadband networks. Such agents could retrieve information on destinations, accommodations, points of interest, pricing, weather, transportation and the like and produce a complete travel package for business or recreation purposes. The agent could make all reservations, plan agendas, complete purchase transactions or purchase event tickets on behalf of the user. It could search the network for a specified period of time to gather all information pertinent to the requests of the traveler.
Large amounts of smaller purchases, such as copier paper, writing implements, common computer goods and office furniture made between businesses could be automated by agents designed for the task. Such agents could determine need, search the network for best availability and pricing information for the required goods (including pre-negotiated discount schedules), make the purchase order, confirm and track orders and shipments and record final receipt of the goods or services.
For investors, agents could be developed to monitor market conditions,
trends and prices for securities such as stocks and bonds or commercially-traded
commodities. The agent could be given authority to make real-time
buy/sell decisions on behalf of the user. This alleviates the
user of the boring task of closely watching markets and the agent
can complete transactions much faster than a human user. Via access
to market data over a broadband network, the agent can keep track
of global investing opportunities.
Many broadband networks must operate upon a resource sharing principal. At different times, bandwidth, data rates, virtual channels and other parameters must be re-allocated amongst different uses and/or users. In many cases, the scheduling of these re-allocations may be driven by a relatively manual process. A master scheduling controller may be used to store information about future network usage and then used to direct sub-controllers to reconfigure network elements to carry out the re-apportioning. Agent technology can be applied in this domain.
In a video-on-demand (VOD) system, users make asynchronous requests for video services. If the service is available, if the user has "approved credit" status and if enough downstream and reverse bandwidth are available, the network may set-up a connection and transfer control to the server and client. During the "session", the network must monitor the health of both the client and server and take action if either side drops off from the session. The complex brokering functions required for VOD call set-up may be effectively handled by agent technology.
Early trials have shown that full video-on-demand (VOD) can be a very expensive undertaking due to server costs and because network resources are not efficiently shared amongst users. Another approach which eliminates some of these disadvantages is near-video-on-demand (NVOD). In an NVOD system, multiple showings of the same program are made, each being offset by some modest time increment (say 15 minutes) from its successor. With proper scheduling, a user may commence viewing of a program at any time, with no longer than a 15-minute wait. For each offset showing, there is only one copy of the program for all viewers. Thus, while removing some real-time user controls (such as rewind, pause), the system can still give weak emulation of these "trick modes" by automatically switching the user to the next showing in the series after a pause, for example. At the same time, bandwidth is used efficiently. Agent technology could be used to extend the standard scheduling algorithms to include full consideration of network utilization and by dynamically scheduling NVOD "showings" in "bandwidth holes" rather than in reserved locations.
While some network protocols, such as ATM, inherently perform bandwidth management based on traffic and quality of service (QoS) contracts, there are always issues of bandwidth reservation, allocation and de-allocation before and during the time when the contracts are being made. A network operator must divvy up its carrying capacity based on business arrangements with network users.
Private or specialty satellite networks are an excellent example because the demand for their bandwidth may vary with time and other factors associated with the network users. For example, the need to schedule a last-minute video conference before closing a deal or a live sporting event that lasts longer than its expected duration may generate unpredictable fluctuations in bandwidth demand. Intelligent network agents could be used to manage this challenge in real-time by negotiating with user agents by taking into account a large set of parameters, including user priority, price limits, bandwidth needed and so on.
Entertainment networks may carry the content of multiple service providers or just the programming of one. In either case, a varying program schedule of movies, premium channels and basic services may need to be balanced against the needs of data users on the same network. Again, agents may be employed to make unassisted decisions which could include contacting the agents of service providers, compiling and referring to typical usage profiles to work out optimal solutions.
Other aspects of network management can benefit from agent approaches.
In many networks, users are not continuously in contact with the network. Also, when a new terminal is introduced into the network, it must receive certain configuration and identity parameters to function. Agents may be employed, either at retail locations, at network operations centers or at the end user premise to perform these initialization functions.
As network use varies over time, various network elements may need to be periodically re-configured. Because the required changes may involve complex relationships, routes, resource allocations and real-time scheduling, agents may be considered to perform these functions.
Some terrestrial networks involve switching technologies such
as ATM, switched Ethernet, frame relay, etc. The management of
such switching techniques and the switches themselves often require
application of sophisticated algorithms and protocols. It is conceivable
that intelligent agents could be developed to automate these tasks
and perform as a community of agents thereby maximizing the potential
of the network..
By utilizing communications networks such as hybrid fiber/coax, satellite and wireless UHF/VHF radio, utility monitoring systems are capable of remote operations on behalf of the consumer and the utility.
This area includes the basic functions of remote meter reading/billing and service connects/disconnects, but could be expanded to encompass usage tracking and customer notification of increases/decreases in usage which are outside of established trends. Agent technology could be used to monitor usage patterns, recognize situations in which suspicious out-of-range usage is occurring and notify the consumer, the utility or take independent action to correct the situation.
Communities of networked agents could be used to detect power outages and signal each other to effect a correction of the outage. Power switching agents could respond to alarms from home- or substation-based agents to re-route power distribution in the regional or local grid.
This is a new form of load management that allows consumers to have more control over their energy consumption by enabling them to program appliances and adjust energy consumption based on the cost of energy. Typically, a system is installed at the customer site and receives signals notifying it of new pricing. For the utility, this form of load management provides a more efficient and cost-effective means of utilizing existing power capacity, rather than increasing capacity through capital purchases. Both consumer and utility could benefit from the addition of Intelligent Agent technologies in this area.
Real-time pricing occurs when a utility charges the customer based
on its cost to supply energy at any given time. By using load
control devices, such as programmable thermostats, the consumer
can specify a different temperature in response to the cost of
energy to gain maximum benefit from electric utility pricing programs.
Agents embedded in home energy products could monitor indoor and
outdoor conditions and the market price of energy to adjust local
consumption based on consumer instructions/preferences given to
it.
This section offers a brief inventory of some important characteristics required to enable agents in broadband networks. Since FIPA has already produced a list of agent standardization categories, this inventory is not exhaustive, but is presented to elucidate some practical issues for agent implementation.
The agent must be implemented in a platform-independent manner. This means using a programming language and/or model that allows an implementation of an agent to be installed and run in many different hardware/software operating environments with little need for modification to the agent. Concepts such as "virtual machines", "p-code", "byte-code" and the like are useful paradigms for achieving such independence.
Agents must not add significant costs to the implementation of user terminals, network elements, element managers or network managers. In general, they must be implementable on the already defined platforms that have been selected for these entities. They must not require special services or support not already available on such entities.
Agents should be structured so that they are able to perform their functions in the presence of numerous network protocols. The agent should be able to automatically adapt to different networking protocols or at least be adaptable through manually-selected dynamic linking of different network drivers without requiring re-coding, re-compiling or other special handling.
Because agents are largely asked to deal with real-world elements and concepts, producing an agent using an object-oriented approach is not only a convenience, but a necessity. Object-oriented approaches also tend to support the kind of extensibility and metamorphosis that advanced agents will require over time. Since agents will often be found in high availability tasks in broadband networks, the re-use of code and related elimination of the re-testing burden that properly implemented objects can provide, would be a welcome attribute of agent approaches.
To provide maximum benefit to a user, an agent will require the ability for independent and autonomous action within prescribed bounds. This would include the ability to query the user before proceeding when the bounds are exceeded.
As discussed, agents may be deployed in applications in which funds transfer, purchase, network integrity, power management and other sensitive factors matter. It goes without saying that strict security measures must be applied to the actions of these agents. This includes agent authentication, message integrity, message privacy and agent integrity (anti-virus) considerations.
Similarly, agents entrusted with financial transactions, network control, power management and the like must behave according to a set of rules or ethics common to all such agents.
In order to take autonomous action, agents will require the capability
of accessing and manipulating existing expert knowledge bases.
These must be expressed in a standardized format which is made
conveniently available to the agent.
Mobility, or the ability to move around in a network or its environment
is often considered an important quality of "Agenthood".
In the broadband networks outlined here, mobility may indeed be
of great use, but it may be observed that even stationary agents
can perform very useful tasks. Thus, for these applications it
would be unwise to require mobility as an absolute requirement
for Agent status. There are numerous other areas in which Agent
standardization can produce major benefits in broadband networks
and it would be most unfortunate if these applications were not
considered in FIPA because of a technicality.
The rapid expansion of the exploitation of broadband networks
of various types is contributing to the development of a global
information economy that can also support robust forms of electronic
commerce. As the flood of available information increases, bewildered
users will ignore this vast resource if it is too difficult to
use or to locate and process desired knowledge. It has been suggested
here that intelligent agents can play a pivotal role in the remedy
to this situation. Likewise, as the networks themselves become
more ubiquitous and complex, their configuration, management and
operation become increasingly daunting tasks. Agent technologies
may again be applied to relieve the operator from the tedious
and repetitive job of network monitoring and fault correction.
Suitably constructed agents can increase network availability
and QoS by acting autonomously in real-time. End-user application
of agents can also extend to proactive financial, commercial and
academic uses. All of the benefits of agent approaches in broadband
networks will be much harder won, however, in the absence of suitable
standards to promote inter-working. It is now becoming apparent
that previous efforts at network standardization (example: MPEG-2,
DVB and ATSC) are providing the propulsion for a vigorous world-wide
roll-out of digital multimedia services in satellite, terrestrial
and wireless systems. It should be an aim and requirement of FIPA
to develop suitable standards for the intelligent agents found
in applications in such networks.