`
`
`
`
`EXHIBIT 1003
`
`
`EXHIBIT 1003
`
`
`
`
`
`
`
`

`

`IEEE 802.9f Draft Standard P802.9f/D7
`
`IEEE STANDARDS FOR LOCAL & METROPOLITAN AREA NETWORKS
`
`Supplement to Integrated Services (IS) LAN Interface at the Medium Access Control
`(MAC) and Physical (PHY) Layers
`
`Remote Terminal Line Power for IEEE 802.9 Integrated Services Terminal Equipment
`
`Prepared by the IEEE 802.9f Editor
`
`Copyright ª 1997 by the Institute of Electrical and Electronics Engineers, Inc.
`345 East 47th Street
`New York, NY 10017, USA
`All rights reserved
`
`This is an unapproved draft of a proposed IEEE Standard, subject to change. Permission is hereby
`granted for IEEE Standards Committee participants to reproduce this document for purposes of IEEE
`standardization activities. Permission is also granted for member bodies and technical committees of
`ISO and IEC to reproduce this document for purposes of developing a national position. Other entities
`seeking permission to reproduce this document for standardization or other activities, or to reproduce
`portions of this document for these or other uses, must contact the IEEE Standards Department for the
`appropriate license. Use of information contained in this unapproved draft is at your own risk.
`
`IEEE Standards Department
`Copyright and Permissions
`445 Hoes Lane, P.O. Box 1331
`Piscataway, NJ 08855-1331, USA
`
`Copyright ª 1997 IEEE. All rights reserved
`This is an unapproved IEEE Standards Draft, subject to change
`
`

`

`Significant Changes
`• Added relationship to ITU-T I.430
`• Added to the critical functionality section those elements requested by Wayne Zakowski.
`• Added some clarification to the use of the asymmetrical modes of the ISLAN remote powering.
`
`Things to do:
`•
`
`

`

`IEEE 802.9f Draft Standard P802.9f/D7
`17 June, 1999
`
`NOTE : This is an internal working document of the IEEE 802.9 Working Group on Integrated Services
`LANs. As such, it is not a standard and may be changed as a result of further work by IEEE 802.9.
`
`POINTS OF CONTACT :
`
`Dhadesugoor R Vaman, Chair
`Director, Advanced Telecommunications Institute
`Stevens Institute of Technology
`Castle Point on the Hudson
`Hoboken, New Jersey 07030
`Tel : (201) 216-5049
`Fax : (201) 216-5057
`email : dvaman@ati.stevens-tech.edu
`
`Robert Bell, Editor
`Selsium Systems Inc.
`341 South Main St.
`Suite 410
`Salt Lake City, Utah 84111
`Tel : (801) 322-4086
`Fax : (801) 322-4083
`email : bbell@incite.com
`
`Page - i
`Copyright ª
` 1997 IEEE. All rights reserved
`This is an unapproved IEEE Standards Draft, subject to change
`
`

`

`P802.9f/D7 IEEE 802.9f Draft Standard
`17 June, 1999
`
`Foreword
`
`(This Foreword is not part of the Proposed Standard P802.9f, Integrated Services (IS) LAN : Remote
`Terminal Line Power for IEEE 802.9 Integrated Services Terminal Equipment).
`
`This standard is part of a family of standards for Local and Metropolitan Area Networks. The relationship
`between this standard and other members of the family is shown below. (The numbers in the figure refer
`to IEEE standard numbers.)
`
`This family of standards deals with the physical and data link layers as defined by the ISO Open Systems
`Interconnection Basic Reference Model (ISO 7498:1984). The access standards define several types of
`medium access technologies and associated physical media, each appropriate for particular applications or
`system objectives. Other types are under investigation.
`
`The standards defining these technologies are as follows :
`
`•
`
`•
`
`•
`
`•
`
`•
`
`IEEE Std 802 : Overview and Architecture. This standard provides an overview to the family of IEEE
`802 Standards. This document forms part of the 802.1 scope of work.
`
`IEEE Std 802.1D : MAC Bridging. Specifies an architecture and protocol for the interconnection of
`IEEE 802 LANs below the MAC service boundary.
`
`IEEE Std 802.1E : System Load Protocol. Specifies a set of services and protocol for those aspects of
`management concerned with the loading of systems on IEEE 802 LANs.
`
`ISO 8802-2 [ANSI/IEEE Std. 802.2] : Logical Link Control.
`
`ISO/IEC 8802-3 [ANSI/IEEE Std 802.3] : CSMA/CD Access Method and Physical Layer
`Specifications.
`
`Page - ii
`Copyright ª
` 1997 IEEE. All rights reserved
`This is an unapproved IEEE Standards Draft, subject to change
`
`

`

`IEEE 802.9f Draft Standard P802.9f/D7
`17 June, 1999
`
`•
`
`•
`
`•
`
`•
`
`•
`
`ISO/IEC 8802-4 [ANSI/IEEE Std 802.4] : Token Bus Access Method and Physical Layer
`Specifications.
`
`IEEE Std 802.5 : Token Ring Access Method and Physical Layer Specifications.
`
`IEEE Std 802.6 : Metropolitan Area Network Access Method and Physical Layer Specifications.
`
`IEEE Std 802.9 : Integrated Services (IS) LAN Interface at the MAC and Physical Layers.
`
`IEEE Std 802.10 : Interoperable LAN/MAN Security (SILS) - Secure Data Exchange (SDE)
`[Currently contains Secure Data Exchange (Clause 2)].
`
`In addition to the family of standards the following is a recommended practice for a common technology :
`
`•
`
`IEEE Std 802.7 : IEEE Recommended Practice for Broadband Local Area Networks.
`
`The reader of this document is urged to become familiar with the complete family of standards.
`
`Page - iii
`Copyright ª
` 1997 IEEE. All rights reserved
`This is an unapproved IEEE Standards Draft, subject to change
`
`

`

`P802.9f/D7 IEEE 802.9f Draft Standard
`17 June, 1999
`
`Contents
`REVISIONS TO IEEE 802.9-1994................................ ................................ ................................ ........... 1
`
`1. OVERVIEW................................ ................................ ................................ ................................ ....1
`1.1.2
`OVERVIEW OF REMOTE TERMINAL LINE POWERING ..............................................................1
`1.2
`NOTATIONS ................................................................................................................................4
`1.3
`SERVICE MODEL .........................................................................................................................4
`1.4
`DOCUMENT ORGANIZATION ........................................................................................................4
`2. REFERENCES................................ ................................ ................................ ................................ 5
`
`3. DEFINITIONS................................ ................................ ................................ ................................ .6
`3.1
`TERMS........................................................................................................................................6
`4. ABBREVIATIONS................................ ................................ ................................ .......................... 6
`
`REMOTE TERMINAL LINE POWER ................................ ................................ ..................... 7
`14.
`ITU-T RECOMMENDATION I.430-1993 ........................................................................................8
`14.1
`IEEE 802.9 POWER FEEDING MODELS ........................................................................................9
`14.2
`PCU DEFINITIONS ...............................................................................................................9
`14.2.1
`TYPES OF ISTES..................................................................................................................9
`14.2.2
`IEEE 802.9 NORMAL AND RESTRICTED POWER FEEDING MODES..........................................10
`14.2.3
`PS1 POWERING METHOD ..........................................................................................................10
`14.3
`NORMAL POWER FEEDING MODE FOR THE PS1 POWERING METHOD ......................................11
`14.3.1
`AU INITIATED RESTRICTED POWER FEEDING MODE FOR THE PS1 POWERING METHOD ...........11
`14.3.2
`PS2 POWERING METHOD ..........................................................................................................11
`14.4
`NORMAL POWER FEEDING MODE FOR THE PS2 POWERING METHOD ......................................12
`14.4.1
`AU INITIATED RESTRICTED POWER FEEDING MODE FOR THE PS2 POWERING METHOD ...........12
`14.4.2
`ISLAN ISTE POWER CONSUMPTION..........................................................................................12
`14.5
`GALVANIC ISOLATION ...............................................................................................................12
`14.6
`LIMITATIONS ON POWER SOURCE AND SINK DURING TRANSITION CONDITIONS ..............................12
`14.7
`PS1 METHOD DIRECT CURRENT IMBALANCE ...............................................................................12
`14.8
`POWER FEED MODE STATUS SIGNALLING.....................................................................................13
`14.9
`ISLAN4-T AND ISLAN20-T STATUS SIGNALLING ..............................................................13
`14.9.1
`ISLAN16-T STATUS SIGNALLING.......................................................................................13
`14.9.2
`ADDITIONAL M-CHANNEL BITS SUPPORTED DURING RESTRICTED POWERING MODES.............14
`14.9.3
`REDUCED CALL SIGNALLING PROCEDURES FOR ISTE INITIATED RESTRICTED POWERING MODE
`14.10
`OPERATION 14
`ANNEX N REMOTE TERMINAL LINE POWERING BACKGROUND (INFORMATIVE)........ 15
`ANNEX N .1
`VOLTAGE SELECTION ....................................................................................................15
`ANNEX N .2
`CONNECTOR IMBALANCE ...............................................................................................15
`ANNEX N .3
`POWER DISTRIBUTION EXAMPLES....................................................................................17
`ANNEX N .3.1
`POWER DISTRIBUTION FOR A PS1 IMPLEMENTATION...................................................17
`ANNEX N .3.2
`POWER DISTRIBUTION FOR A PS2 IMPLEMENTATION...................................................18
`ANNEX O CRITICAL FUNCTIONALITY FOR REMOTE TERMINAL LINE POWERING
`(NORMATIVE)................................ ................................ ................................ ................................ .....21
`ANNEX O .1
`EMERGENCY FUNCTIONALITY ........................................................................................21
`ANNEX O .1.1
`USER INTERFACE DEVICE...........................................................................................22
`ANNEX O .1.2
`USER INTERFACE CONTROL FUNCTION .......................................................................22
`ANNEX O .1.3
`ISLAN16-T PHYSICAL LAYER INTERFACE..................................................................22
`ANNEX O .1.4
`PROTOCOL CONTROL FUNCTION ................................................................................22
`Page - iv
`Copyright ª
` 1997 IEEE. All rights reserved
`This is an unapproved IEEE Standards Draft, subject to change
`
`

`

`IEEE 802.9f Draft Standard P802.9f/D7
`17 June, 1999
`
`ANNEX O .1.5
`ANNEX O .2
`ANNEX O .3
`
`
`USER INFORMATION STREAM MAPPING FUNCTION.......................................................22
`ROUTINE FUNCTIONALITY ..............................................................................................23
`SUMMARY.....................................................................................................................23
`
`Figures
`
`FIGURE 1-1 IEEE 802.9F SCOPE OF INTEREST.............................................................................................2
`FIGURE 14-1 POWER SOURCE 1 .................................................................................................................11
`FIGURE 14-2 POWER SOURCE 2 .................................................................................................................12
`FIGURE ANNEX N -1 TYPICAL CONNECTORIZATION EXAMPLE....................................................................16
`FIGURE ANNEX N -2 ISOLATION TRANSFORMER DETAIL ............................................................................16
`FIGURE ANNEX N -3 PS1 POWER DISTRIBUTION EXAMPLE ........................................................................17
`FIGURE ANNEX N -4 PS2 POWER DISTRIBUTION EXAMPLE........................................................................19
`FIGURE O-1 SCOPE OF INTEREST ...............................................................................................................21
`
`Tables
`
`TABLE 14-1 RJ-45 CONTACT ASSIGNMENTS................................................................................................7
`TABLE 14-2 POWER SINK CONTACT ASSIGNMENTS......................................................................................7
`TABLE ANNEX N -1 CABLE RESISTANCE IN OHMS AT 100 METERS .............................................................15
`TABLE ANNEX N -2 CONNECTOR EFFECTS ................................................................................................16
`
`Page - v
`Copyright ª
` 1997 IEEE. All rights reserved
`This is an unapproved IEEE Standards Draft, subject to change
`
`

`

`P802.9f/D7 IEEE 802.9f Draft Standard
`17 June, 1999
`
`This page intentionally left blank.
`
`Page - vi
`Copyright ª
` 1997 IEEE. All rights reserved
`This is an unapproved IEEE Standards Draft, subject to change
`
`

`

`IEEE 802.9f Draft Standard
`
`P802.9f/D7
`17 June, 1999
`
`Revisions to IEEE 802.9-1994
`
`The contents of this document will be incorporated into IEEE Std 802.9 in a future edition. The clauses of
`this document are ordered to parallel the order of clauses in the base standard. This supplement is
`intended to be used in conjunction with IEEE Std 802.9-1994. Editing instructions necessary to
`incorporate this supplement into IEEE Std 802.9 are provided in bold italics.
`
`1. Overview
`Add the following as Subclause 1.1.2 of IEEE 802.9.
`
`1.1.2 Overview of Remote Terminal Line Powering
`*NOTE—All underlined text should be deleted when this document is merged with IEEE Std 802.9 if
`IEEE 802.9a-1995 has also been included into IEEE 802.9. This supplement should not be merged
`without IEE 802.9a-1995.
`ISLAN (IEEE Std 802.9-1995) provides for the integration of voice, data, and video services to the
`desktop. A desired step in the evolution of this integration is improved availability. In the case of voice
`services, i.e. telephony, users have come to expect service under all conditions including loss of power.
`An ISLAN compatible ISTE should be able to provide basic voice service regardless of the state of the
`personal computer, building power, weather, time of day, etc. Achieving this level of service has several
`implications. 1). The network should be very reliable and have power backup. 2) The desktop
`instrument should have power available to operate (at least for basic voice services) under all conditions.
`IEEE 802.9f addresses the second item, provision for supplying power to an end instrument from the
`ISLAN network. It should be noted however that this is an optional implementation specification. It is
`NOT required that an ISTE accept remote terminal line powering in order to be conformant to IEEE Std
`802.9. Neither is it mandatory for access units to provide remote terminal line powering. This standard is
`provided so as to standardize the characteristics by which such remote terminal line powering is provided
`so as to aid interoperability.
`
`1.1.2.1 Scope
`IEEE draft standard 802.9f specifies the details of providing power from an ISLAN Access Unit (AU) to
`an ISLAN compliant ISTE via one of two methods; 1) PS1 powering over the signal pairs, or 2) power
`over additional cabling (PS2 powering). Both methods are specified in IEEE 802.9f. The following
`diagram, Figure 1-1 illustrates the scope of IEEE 802.9f.
`
`Page - 1
`Copyright ª 1997 IEEE. All rights reserved
`This is an unapproved IEEE Standards Draft, subject to change
`
`

`

`P802.9f/D7
`17 June, 1999
`
`IEEE 802.9f Draft Standard
`
`IEEE
`802.9f
`Scope of
`Interest
`
`ISLAN
`AU
`
`Remote
`Terminal
`Power Source
`
`Physical Wiring
`
`ISLAN
`
`Remote
`Terminal
`Power Sink
`ISLAN
`ISTE
`
` Figure 1-1 IEEE 802.9f Scope of Interest
`
`1.1.2.2 Purpose
`The purpose of this standard is to provide a set of methodologies which will allow a remote terminal to be
`powered from a central source. There are multiple ways of providing reliable power to an ISTE. The
`primary means are :
`1. A local power supply with provision for power backup such as a mini-UPS.
`2. Power Source 1 or PS1 allows power to be sourced to the desktop instrument from a centralized
`source across the same wiring used for data transfer.
`3. Power Source 2 or PS2 powering allows power to be sourced from a centralized source across an
`additional pair of wires.
`This standard shall specify only methods two and three.
`
`The first possibility (local power with backup) is still relatively expensive particularly as the size of
`installations become larger. Local powering may make sense for cases where power backup is already in
`place such as servers. Any further discussion of local powering is considered beyond the scope of IEEE
`802.9f.
`
`PS1 powering has the following properties:
`• Usage of existing ISLAN cabling (power is provided over the signal pairs) is possible.
`• Modifications to existing ISLAN networks are relatively minor--mainly involving a change to the
`filter module.
`• Existing non-powered 10Base-T devices and ISLAN ISTEs will be unaffected when connected to
`an AU capable of providing power.
`• Total power is limited to basic voice service due to restrictions imposed by consideration of signal
`interference and DC components of the signal
`
`PS2 powering has the following properties:
`• There is a minor effect on signal pairs.
`• There fewer limitations on powering.
`• There is a requirement for an additional wire pair.
`
`Page - 2
`Copyright ª 1997 IEEE. All rights reserved
`This is an unapproved IEEE Standards Draft, subject to change
`
`

`

`IEEE 802.9f Draft Standard
`
`P802.9f/D7
`17 June, 1999
`
`By specifying the requirements and procedures for these two powering methodologies, interoperability
`will be realized between powered AUs and powered/unpowered ISTEs. Furthermore, an ISLAN network
`will be capable of providing the same level of service currently associated with ISDN Basic Rate (BRI)
`devices regarding telephony as well as the additional transport of high-speed digital video and data. This
`level of service implies that the voice telephony capability (e.g. placing an emergency phone call) is
`available regardless of the state of the local PC. If this capability is provided, then, the ISLAN system
`could provide a total communications solution for the end user. ISLAN would then represent a truly
`“integrated service”.
`
`Page - 3
`Copyright ª 1997 IEEE. All rights reserved
`This is an unapproved IEEE Standards Draft, subject to change
`
`

`

`IEEE 802.9f Draft Standard
`
`P802.9f/D7
`17 June, 1999
`
`1.2 Notations
`No Additions
`
`1.3 Service Model
`No Additions
`
`1.4 Document Organization
`
`This standard is organized into the following clauses:
`
`Clause 1.1.2
`
`Overview
`
`Clause 2
`
`Clause 3
`
`Clause 4
`
`References
`
`Definitions
`
`Abbreviations
`
`Clause 14
`
`Remote Terminal Line Power
`
`Clause 14.1
`
`PS1 Powering Method
`
`Clause 14.2
`
`PS2 Powering Method
`
`Annex N
`
`Annex O
`
`Remote Terminal Line Power Background
`
`Remote Terminal Line Power Critical Functions
`
`Page - 4
`Copyright ª 1997 IEEE. All rights reserved
`This is an unapproved IEEE Standards Draft, subject to change
`
`

`

`IEEE 802.9f Draft Standard
`
`2. References
`
`Add to References
`
`ITU-T Recommendation I.430 :1988, Basic Rate - Layer 1 Specification.
`
`P802.9f/D7
`17 June, 1999
`
`Page - 5
`Copyright ª 1997 IEEE. All rights reserved
`This is an unapproved IEEE Standards Draft, subject to change
`
`

`

`P802.9f/D7
`17 June, 1999
`
`3. Definitions
`
`3.1 Terms
`
`Add to definitions.
`Term
`AU initiated restricted mode
`ISTE initiated restricted mode
`ISTE type one
`ISTE type two
`
`ISTE type three
`
`Normal power feeding mode
`
`Phantom Power
`
`Power feeding
`
`Power Source 1
`
`Power Source 2
`
`Restricted power feeding mode
`Third Pair Powering
`
`IEEE 802.9f Draft Standard
`
`Definition
`A restricted power feeding mode initiated as a result of events at the AU
`A restricted power feeding mode initiated as a result of events at the ISTE.
`An ISTE whose normal powering source is locally provided.
`An ISTE whose normal powering source is remote power feeding from the
`AU to which it is attached.
`An ISTE whose normal powering source is locally provided but which can
`operate in a reduced capability mode from power provided through remote
`power feeding from the AU to which it is attached.
`This power feeding mode is in operation when the ISTE is receiving its
`normal powering.
`
`A method of providing power to a remote entity by using the information
`carrying pairs of a communications cable to also carry DC power.
`The process of providing power to an end device from a centralized source
`such as an AU. The power may be provided as “Phantom Power” or as “Third
`Pair Power”.
`A method for providing line power between an AU and an ISTE that utilizes
`the signal pair wires for power distribution. Also known as PS1.
`
`A method for providing line power between an AU and an ISTE that utilizes
`an additional wire pair for power distribution. Also known as PS2.
`This power feeding mode is in operation during exception conditions.
`
`A method of providing power to a remote entity by using an additional pair of
`wires in a communications cable to carry DC power.
`
`4. Abbreviations
`
`Add to abbreviations.
`
`PS1: Power Source 1.
`PS2: Power Source 2.
`PCU: Power Consumption Unit.
`NPCU: Normal Power Consumption Unit
`RPCU: Restricted Power Consumption Unit
`
`Page - 6
`Copyright ª 1997 IEEE. All rights reserved
`This is an unapproved IEEE Standards Draft, subject to change
`
`

`

`IEEE 802.9f Draft Standard P802.9f/D7
`17 June, 1999
`
`Add this as Clause 14 in its entirety as follows
`
`14. Remote Terminal Line Power
`Remote terminal line power is a set of methods for providing power to an ISTE device utilizing the AU-to-ISTE
`cabling. Although the remote terminal line power requirements hereafter defined are probably not sufficient to
`power a device such as a PC or workstation, they are sufficient to power a secondary device such as an audio
`instrument. ITU-T Recommendation I.430 is used as the reference model for this standard. In the 10BaseT mode of
`operation, remote powering shall not be supported. This insures that 10BaseT services are unaffected by this
`optional feature.
`
`If remote terminal line powering is implemented, the following are mandatory requirements.
`• Power sources at the AU must provide current limiting devices not to exceed 500mA.
`• The rate of change of current drawn by an ISTE (for example, when connected) shall not exceed 5
`milliamps per microsecond.
`ISTEs that provide power sinks shall provide galvanic isolation between power sources and the earth
`grounds of additional sources of power and/or equipment.
`
`•
`
`This last provision is intended to preclude earth loops or paths which could result in currents that would interfere
`with the satisfactory operation of the ISTE. It is independent of any requirement, for such isolation, related to
`safety which are already specified in IEEE 802.3. It shall not be interpreted to require isolation which conflicts
`with necessary provisions for safety.
`
`Table 14-1 provides the connector assignments for the RJ-45 connectors used in several common LAN types. It is
`intended as information only and for comparison between the connector assignments.
`
`Contact
`Assignment
`s
`1
`2
`3
`4
`5
`6
`7
`8
`
`I.430
`ISDN/BRI
`
`IEEE 802.3I
`10BASE-T
`
`IEEE 802.3u
`100BASE-T4
`
`IEEE 802.5b
`Token Ring
`
`IEEE 802.9
`ISLAN
`
`IEEE 802.12
`100BASE-VG
`
`TD+
`PS3(+)
`TD-
`PS3(-)
`Transmit (+) RD+
`Receive (+)
`Not Used
`Receive (-)
`Not Used
`Transmit (-)
`RD-
`PS2 (-)
`Not Used
`PS2 (+)
`Not Used
`
`TX_D1+
`TX_D1-
`RX_D2+
`BI_D3+
`BI_D3-
`RX_D2-
`BI_D4+
`BI_D4-
`
`Unassigned
`Unassigned
`Tx
`Rx
`Rx
`Tx
`Unassigned
`Unassigned
`
`TD+
`TD-
`RD+
`Not Used
`Not Used
`RD-
`PS2 (-)
`PS2 (+)
`
`TPIO:0+
`TPIO:0-
`TPIO:1+
`TPIO:2+
`TPIO:2-
`TPIO:1-
`TPIO:3+
`TPIO:3-
`
`Table 14-1 RJ-45 Contact Assignments
`Table 14-2 shall serve as the reference for polarity assignment at the ISTE RJ-45 connector.
`
`Page - 7
`Copyright ª1997 IEEE. All rights reserved
`This is an unapproved IEEE Standards Draft, subject to change
`
`

`

`P802.9f/D7 IEEE 802.9f Draft Standard
`17 June, 1999
`
`Contact
`1
`2
`3
`4
`5
`6
`7
`8
`
`MDI Signal
`Transmit Data +
`Transmit Data -
`Receive Data +
`(Not used)
`(Not used)
`Receive Data -
`Power Source 2
`Power Source 2
`
`DC Polarity
`+
`+
`-
`
`-
`-
`+
`
`Table 14-2 Power Sink Contact Assignments
`There exists a relationship between ITU-T Recommendation I.430-1993 and IEEE 802.9f. This relationship is
`presented in the following paragraphs.
`
`14.1 ITU-T Recommendation I.430-1993
`ITU-T Recommendation I.430 Clause 9 defines a system of power feeding which is to be provided for powering
`ISDN terminal devices. It is designed to allow power to be provided from a point remote from the end device and
`yet allow for both normal conditions and exception conditions. Within the I.430 powering model, it is assumed that
`the power is supplied at the network side of the S/T reference points. In the case of central office connected ISDN
`terminals, this point is on the customer premise. In the case of typical PBX implementations, the S/T interface
`point is located at the PBX interface card or equivalent. It is implicit within the context of I.430 that the end device
`would need to be aware of the powering capabilities of its power source but that at no time would it be necessary
`for the powering point to be aware of the powering requirements of the end device.
`
`I.430 defines three power sources designated PS1, PS2, and PS3. PS1 and PS2 power sources provide power from
`the NT (network termination) toward the TE (terminal adapter). PS1 and PS2 have the same meanings when used
`within the context of IEEE 802.9. PS3 is a provision which allows power to be feed from the TE to the NT but “is
`not subject to CCITT Recommendation”1. There is no equivalent powering source in IEEE 802.9.
`
`I.430 introduces the concepts of normal mode power feeding and restricted mode power feeding. These two modes
`are network termination point centric. In the first mode, the network power source is capable of providing a full
`measure of power feeding. This power is defined in terms of power consumption units. A normal power
`consumption unit is 100 mW of power.
`
`In the second mode, the network power source is no longer capable of supplying the full power feed. In this mode,
`indicated by a reversal of polarity of the power feed, designated terminals must reduce their power consumption
`and non-designated terminals must effectively “go to sleep”. The concept of designated and non-designated
`terminals comes from the “passive bus” configuration defined for ISDN. In the “passive bus” configuration, more
`than one end terminal is connected to the “T” reference point. Only one terminal may be selected as the
`“designated terminal” within a group of terminals on a “passive bus”. A restricted power consumption unit is
`equivalent to 95 mW. I.430 states that “The difference in units is required to allow adequate margins for power
`consumed be non-designated terminals in restricted mode”2.
`
`Voltage differences exist between normal and restricted power feeding modes. In normal mode power feeding, an
`NT operating in PS1 mode is required to provide voltage of 34V to 42V (optionally up to 56.5 V if the NT is using
`a PBX style 48 V supply system) at the output of the NT when supplying up to the maximum available power3. In
`restricted mode operation, an NT operating as a PS1 must supply at the output of the NT voltage within the range
`34V to 42V ( optionally up to 56.6V) when supplying up to its rated maximum power which is not less than 420
`
`1 ITU-T Recommendation I.430-1993 Clause 9.1.2
`2 ITU-T Recommendation I.430-1993 Clause 9.3.1
`3 ITU-T Recommendation I.430-1993, Clause 9.2.2.1
`
`Page - 8
`Copyright ª 1997 IEEE. All rights reserved
`This is an unapproved IEEE Standards Draft, subject to change
`
`

`

`IEEE 802.9f Draft Standard P802.9f/D7
`17 June, 1999
`
`mW4. NTs operating in PS2 mode must supply the same voltages as defined for the PS1 mode of operation. There
`is a set of similar requirements defined for the power and voltage levels at the TE which takes into account the line
`losses of the two powering models5.
`
`Galvanic isolation is defined as a minimum of 1 MW when measured at 500 VDC 6.
`
`Finally, a description of characteristics relative to current availability and time frames during the transition from
`normal to restricted and restricted to normal modes of power feeding are presented in ITU-T Recommendation
`I.430-1993 Clause 9.7. The effects of current imbalance are presented in ITU-T Recommendation I.430-1993,
`Clause 9.8.
`
`14.2 IEEE 802.9 Power Feeding Models
`IEEE 802.9f defines in environment which differs somewhat from that presented and presumed in ITU-T
`Recommendation I.430. Within I.430, the requirements are assumed to flow from the network termination unit
`(NT) towards the terminating equipment (TE). The role of the I.430 NT is represented by the IEEE 802.9 AU in
`the current specification. The role of the I.430 TE is similarly represented by the IEEE 802.9 ISTE. Within the
`IEEE 802.9 network, powering and capabilities indications need to flow in both directions.
`
`I.430 also introduces the concepts of a normal power feeding mode and a restricted power feeding mode. Within
`the context of I.430, normal power feeding mode means that the NT is capable of providing the maximum amount
`of power specified to all TE’s attached to the NT. Restricted power feeding mode indicates that a limited amount of
`power is available to the NT. One TE is “designated” to allow it to consume a limited though relatively large
`amount of power from the TE. All other TE’s attached to the NT are restricted to very low levels of power
`consumption. Because of the structure of an IEEE 802.9 network, there is no requirement to differentiate between
`“designated” and “non-designated” ISTEs since only one ISTE can be attached to a “port” of an AU. However,
`within the IEEE 802.9 environment, there is a need to allow for modifications of the power considerations due to
`events either at the AU or at the ISTE. These will be discussed below.
`
`Power Source 1, also know as PS1 utilizes contacts 1,2,3,6. Power Source 2, also known as PS2, utilizes contacts 7
`and 8. Typically, an ISLAN AU implementation will include at most one of these power feeding methods.
`However, for compatibility sake, an ISLAN ISTE should implement both power feeding methods with user
`selection between them. It should be noted that the PS1 method is the more desirable mode of implementation. If
`remote power feeding is used, subclauses 14.3 and 14.4 describe each of these methods in detail. Note that AU-to-
`AU interconnections shall not use remote power feeding.
`
`14.2.1 PCU definitions
`A normal power consumption unit (NPCU) shall be defined as 100 mW available at the ISTE. A restricted power
`consumption unit (RPCU) is defined as 95 mW available at the ISTE.
`
`14.2.2 Types of ISTEs
`For the purposes of this specification, there are three types of ISTEs which must be considered. Type one ISTEs
`receive their normal powering from a source which is local to the ISTE and are not capable of deriving power from
`a remote power feeding arrangement. However a type one ISTE is capable of operating in a reduced capabilities
`mode when the local power is not available and it is powered from the AU. Type two ISTEs derive all of their
`power from remote power feeding. A type two