By Chris Burke, Chairman, IETF Web Elucidation of Internet Related Developments WG

At this writing (February 8, 2000) the IETF has more than 100 active working groups clustered in 8 areas of specialization. No area of specialization deals specifically with "wireless internet", but activities related to wireless internetworking can be found in each of the areas.

In this article I’ll define "wireless internet", identify some uniquely wireless issues in internet standardization, and survey the work of the IETF that has, in my opinion, the greatest impact on evolution and deployment of wireless internet.

"Wireless" refers to ways of transmitting information using radio signals or light traveling through space (no wires or fiber-optics). "Internet" refers to the global information system that:

"Wireless internet" is simply that part or parts of the internet, for which the communications and related infrastructure described in item (iii) above, are provided using wireless data transmission media such as radio signals or light.

The wireless internet is part of the internet, and so nearly every activity, RFC, and standard of the IETF applies to the wireless internet. Exceptions include certain IETF Internet Area activities related to transmission of internet protocols over specific non-wireless media such as fiber-channel or IEEE 1394 "firewire".

Engineering the wireless internet presents unique technical challenges. The frequencies used for radio transmission are a scarce resource – so scarce that most governments around the world carefully regulate their use for information transmission.

Wireless internet signals travel freely through space, but their travel is limited by government regulations on transmitter power and the signals can be blocked or corrupted unintentionally by walls, moving vehicles, mountains, or even bad weather. Signals can arrive at unintended receivers, causing interference with other means of communication, or duplication of data. Wireless communication also presents a security challenge - anyone with the right equipment can eavesdrop on unsecured wireless internet signals without "tapping a wire".

One very important internet protocol, Transmission Control Protocol (TCP), relies on assumptions that are not valid on some wireless networks. TCP includes a congestion control mechanism intended to prevent network gridlock during periods of high usage. However, this mechanism uses packet loss (failure of information to arrive when expected) as an indicator of congestion. In wireless neworks packet loss commonly occurs for a variety of reasons unrelated to congestion. TCP reacts to packet loss by trying "less hard" to send data, when a more appropriate response on a wireless network might be just the opposite.

In many cases, the engineer’s goal in choosing a wireless transmission medium is to achieve mobility; those using the wireless internet want to move around while doing so, without interrupting their interaction with high level services like web browsing, e-mail, group collaboration, or gaming. The desire for mobility leads to requirements on networking technology and also limits the compute-power and program storage available to implement internet protocols.

Some wireless transmission media, such as satellites, time-delay data significantly. Other wireless media, such as narrow-band packet radio, transmit data slowly in comparison with typical dial-up internet access.

Wide-are wireless internets are often operated for profit, by the same companies that operate cellular telephony systems. The wireless medium itself is scarce, and the opportunity cost of using the medium for wireless internet access is often high: a customer might pay $12 / hour to talk over a cell phone using network resources that might otherwise enable wireless internet access. To meet the needs of end users, engineers designing applications for use on the wireless internet often prioritize minimizing the amount of network resource used by the application over creating rich functionality. This has a direct impact on the engineering of transport, security, and application-layer protocols.

The unique challenges and resource costs of building the wireless internet can cause engineers designing wireless internets, and engineers designing wired internets, to find different solutions and architectures optimal. When such engineers meet in IETF working groups, their challenge is to find solutions that meet the common need without over-compromising either.

The wireless internet is part of the internet, and so nearly every activity, RFC, and standard of the IETF applies to the wireless internet. The working groups highlighted here indicate only my own perspective – the subjects that I, as a wireless internet engineer, find to have the greatest potential impact on deployment of wireless internets.

Applications Area

The Applications Area of the IETF is concerned with protocols used to implement high level services on the internet. Some of these high level services have strong functional similarity to services like paging and voice telephony that have traditionally been offered over dedicated wireless networks.

IETF work on high level services creates both competitive alternatives and an evolutionary path for traditional wireless services. Applications Area work of particular interest to engineers working on the wireless internet includes:

• Application Configuration Access Protocol (acap), for standards related to communicating user preferences and "home environment" settings between clients and servers.
• Content Negotiation (conneg), for standards related to automatically reformatting or transcoding internet content based on display size, bandwidth, and other capabilities of the subscriber equipment.
• Hyper-Text Transfer Protocol (http), for standards related to the evolution and efficiency improvements of the basic world-wide-web protocol alternative to the WAP protocol stack.
• Internet Open Trading Protocol (iotp), for standards related to interoperable e-commerce over wired and wireless networks.
• Instant Messaging and Presence Protocol (impp), for standards related to two-way paging and location-based services over the internet.
• Resource Capabilities Discovery (rescap), for standards related to determining the display and memory capabilities of subscriber equipment prior to message transmission.

General Area

Currently the General Area of the IETF has only one working group. Known as poisson (Process for Organization of Internet Standards ONg), this group discusses and documents the standards development process of the IETF, including IETF policy for interaction with other standards bodies such as ETSI and TIA.

Internet Area

Working groups in the IETF Internet Area may meet to agree on standards for transmission of IP datagrams over specific media types. Currently, working groups are discussing IP Over Fiber Channel, IP Over IEEE 1394, and IP Over Cable Data Network. None of the current discussions are specific to wireless media.

Several working groups in the Internet Area are discussing issues about which engineers working on wireless internet deployment might have a unique view of requirements. These include:

• Dynamic Host Configuration (dhc), for standards related to dynamic assignment of IP addresses, a technique used by some wireless carriers to simplify configuration and extend the IPv4 address space.
• IP Next Generation (ipngwg), for standards related to the next-generation IP datagram, IPv6, which has many beneficial features for wireless networks.
• Internetworking Over Non-Broadcast Multiple Access (ion), for standards related to IP over virtual circuits, ATM, X.25, and related technologies currently in use by wireless operators.
• Layer Two Tunneling Protocol Extensions (l2tpext), for standards related to transmitting / tunneling the PPP protocol over various (including wireless) media types
• Point-to-Point Protocol Extensions (pppext), for standards related to new features of the PPP protocol that might be needed to support wireless media.
• Service Location Protocol (slp), for standards and APIs related to local-area location-based services.
• Zero Configuration Networking (zeroconf), for standards related to "over-the-air" provisioning of new network users.

Operations and Management Area

The Operations and Management Area of the IETF forms working groups to develop network management standards.

Many of the working groups in this area meet to specify Simple Network Management Protocol (SNMP) Management Information Blocks (MIBs) that provide management information about specific data transmission media – including, potentially, wireless media.

Another large set of Operations and Management Area working groups meet to specify management techniques for making Quality of Service (QoS) guarantees and optimizations in wired and wireless internets.

The work of the Operations and Management area includes all aspects of internet network management. Working groups discussing topics of special interest to wireless internet engineers include:

• Authentication, Authorization, and Accounting (aaa), for standards related to management of mobility, roaming, billing records, policy, and network access security.
• Benchmarking Methodology (bmwg), for standards related to how the performance of various internet technologies (including wireless technologies) will be measured and compared.
• Configuration Management with SNMP (snmpconf), for standards related to management of QoS provisioning.
• Distributed Management (disman), for standards related to distributed wireless network management.
• Internet Traffic Engineering (tewg), for standards related to performance optimization, modeling, QoS provisioning across multiple autonomous systems (e.g. wired and wireless hops), and control of internet traffic.
• MBONE Deployment (mboned), for standards related to deployment of internet multicast (e.g. multimedia conference call) routing protocols.

• Network Access Server Requirements (nasreq), which is developing a requirements document for user-based service authentication, authorization and usage accounting during roaming and virtual-private network access.

• Next Generation Transition (ngtrans), which is developing recommendations for deployment of IPv6 in wired and wireless internets.
• Policy Framework (policy), for standards related to representation and exchange of device configuration information to support managed QoS.

• Remote Authentication Dial-In User Service (radius), for standards related to communicating authentication and authorization information between a Network Access Server and a central authentication & authorization server (e.g. VLR/HLR).

• Remote Network Monitoring (rmonmib), for standards defining a set of managed objects for remote monitoring of networks, including QoS statistics.

• Resource Allocation Protocol (rap), for standards defining communication and control of QoS policy between network elements.

• Roaming Operations (roamops), for standard procedures, mechanisms and protocols to support user (not subscriber equipment) roaming among groups of Internet service providers (ISPs) similar to the virtual home environment concept being deployed in 3G wireless networks.

Routing Area

Working groups in the IETF Routing Area discuss and specify techniques for moving information around in the internet (routing) based on IP addresses and other criteria. Working groups of special interest to wireless internet engineers include:

• Border Gateway Multicast Protocol (bgmp), for standards related to optimization of "group call" routing

• General Switch Management Protocol (gsmp), for standards related to internet switch configuration control and reporting, port management, connection control, QoS and traffic engineering control and the reporting of statistics and asynchronous events.

• Internet Protocol Routing for Wireless/Mobile Hosts (mobileip), for standards related to allowing the use of a single, static IP address while roaming across network / carrier boundaries.
• IS-IS for IP Internets (isis), for standards related to traffic engineering in large wired or wireless networks.
• Open Shortest Path First (ospf), for standards related to traffic engineering in large wired or wireless networks.
• Inter-Domain Multicast Routing (idmr), for standards related to routing a "group call" across network / carrier boundaries.
• Inter-Domain Routing (idr), for standards related to policy-based routing across network / carrier boundaries.
• Mobile Ad-hoc Networks (manet), for standards related to self-organizing wireless networks.
• Multiprotocol Label Switching (mpls), for standards related to traffic aggregation, QoS management, and interworking with ATM switches.
• Protocol Independent Multicast (pim), for standards related to using a specific multicast technology (PIM) over various underlying networks (including wireless networks).
• Unidirectional Link Routing (udlr), for standards related to wireless one-way broadcast transmission using internet protocols.
• Virtual Router Redundancy Protocol (vrrp), for standards related to soft fail-over of internet routers to increase system availability and scalability.

Security Area

The IETF Security Area addresses protocol security issues for all of the other areas. Security is important in all aspects of internet communication, but is of special interest to wireless internet engineers due to the relative ease of intercepting, spoofing, or interfering with a radio signal.

Security Area working groups that might be of special interest to wireless internet engineers include:

• Authenticated Firewall Traversal (aft), for standards related to secure interworking between public and private networks.

• Common Authentication Technology (cat), for standards related to distributed authentication, integrity, confidentiality, and authorization services.

• Internet Protocol Security Policy (ipsp), for standards related to representing, discovering, exchanging and managing the policies that control access to network resources in a scalable, secured and reliable fashion.

• Internet Protocol Security Protocol (ipsec), for standards related to providing cryptographic security services that support combinations of authentication, integrity, access control, and confidentiality for internet protocols.

• One Time Password Authentication (otp), for standards related to authentication mechanisms that resist eavesdropping.
• Simple Public Key Infrastructure (spki), for standards related to light-weight and effective security measures for wired and wireless internets.
• Web Transaction Security (wts), for standards related to secure (e.g. e-commerce) transactions using browsers and micro-browsers.

Transport Area

Transport Area working groups discuss issues and author standards related to transmitting streams of data over wired and wireless internets. This is a very rich area, with many topics of special interest to wireless internet engineers, including:

• Audio/Video Transport (avt), for standards related to real-time transmission of audio (e.g. telephony) and video (e.g. television) using internet protocols.
• Differentiated Services (diffserv), for standards related to end-to-end Quality of Service (QoS)

• Internet Protocol Performance Metrics (ippm), for standards related to measuring and comparing quality, performance, and reliability of Internet data delivery services.

• Internet Protocol Telephony (iptel), for standards related to defining a uniform telephony call model and representing and distributing the capabilities of telephony gateways.
• Integrated Services (intserv), for standards related to end-to-end Quality of Service (QoS).

• Integrated Services over Specific Link Layers (issll), to define specifications and techniques needed to implement Integrated Services QoS capabilities within specific network technologies such as wireless networks.

• Media Gateway Control (megaco), for standards related to interworking between internet telephony and other telephony systems.
• Multiparty Multimedia Session Control (mmusic), for standards related to initiating and coordinating multiparty conference calls over the internet.
• PSTN and Internet Internetworking (pint), for standards related to interworking between internet-based resources and the Public Switched Telephone Network (PSTN/POTS/Cellular).
• Performance Implications of Link Characteristics (pilc), for standards related to optimal support of internet protocols using specific wireless media, and the use of proxy servers to enhance performance over low data rate or time-delayed media.
• Reliable Multicast Transport (rmt), for standards related to "group call" transmission of content using the internet.
• Resource Reservation Setup Protocol (rsvp), for standards related to end-to-end Quality of Service (QoS).
• Service in the PSTN/IN Requesting Internet Service (spirits), for standards related to interworking between Intelligent Network (IN) wired and wireless telephony systems and internet-based resources.
• Signaling Transport (sigtran), for standards related to interworking between internet-based resources and the Public Switched Telephone Network (PSTN/POTS/Cellular).
• Telephone Number Mapping (enum), for standards related to mapping telephone numbers to internet resources.
• Transport Area Working Group (tsvwg), for miscellaneous transport-related standards activities that do not have dedicated working groups.

User Services Area

Unlike other IETF areas, the User Services Area does not develop internet standards. Rather, it serves as an end-user advocate and identifies methods to improve the quality of information available to users of the Internet, and initiates projects designed to assist individuals and organizations that support Internet users.

The Web Elucidation of Internet Related Developments (weird) working group that wrote this document on wireless internet issues is part of the User Services Area.

Here are 10 topics of interest to engineers developing wireless internets, a brief description of each, and a list of current IETF activities related to each topic.

Note that the Internet Research Task Force (IRTF) is a forum for discussion of pre-standardization research in many of these areas. For more information, consult the IRTF home page at http://www.irtf.org/.

(THIS SECTION NOT FINISHED – OUTLINE ONLY)

Matching Internet Protocol Requirements to Bandwidth, Delay, Jitter, Time-Variance, and Error Rate of the Medium

Optimal Network Resource Allocation

Usage Metrics for Cost Recovery

Security of All Parties

Mobility and Dynamic Network Topology

Small Internet Hosts

Emulation of High Level Services that Predate the Internet

Interworking with Legacy Wireless Telecommunication Systems

New High Level Services

IETF Policies, Alliances, Liaisons, and Sharing of Responsibility With Other Wireless Telecommunication Industry Standards Development Organizations

Birds-Of-a-Feather (BOF) is a name given by the IETF to an open meeting to discuss creation of new IETF working groups.

If you are working on any aspect of wireless internet that would benefit from the IETF standards process, but don’t see an IETF working group discussing your issues, why not host a BOF at an IETF meeting to find out who else around the world shares your goals?

In the interest of attracting the largest group of interested parties, BOF meetings are formal agenda items at IETF meetings, and must be sponsored by one of the IETF Area Directors. Instructions for requesting a BOF on the IETF meeting agenda are on-line at http://www.ietf.org/meetings/1bof-procedures.txt.

WEIRD is the Web Elucidation of Internet Related Developments working group of the Internet Engineering Task Force. WEIRD provides information through its web site to raise engineering community and end-user awareness of IETF activities.

We chose the unorthodox name, WEIRD, to reflect the unusual structure and deliverables of the working group. Most IETF working groups have a fixed period of existence in which to develop specific standards-related deliverables known as RFCs. In contrast, the WEIRD working group uses web media to report on current IETF working group and pre-working-group (known as BOF) activities, dependencies and interrelationships among specific IETF WG and BOF activities, IAB / IESG / Secretariat issues and topics of interest to the internet engineering community.