(i) Terminating subscriber lines at a location remote from the serving central office;

(ii) Concentrating the subscriber lines over a few transmission and supervisory paths to the serving central office; and

(iii) Terminating the lines at the central office without loss of individual identity. A subscriber connected to a line concentrator shall be capable of having essentially the same services as a subscriber connected directly to the central office equipment (COE). Intra-unit calling among subscribers connected to the concentrator may be provided, but is not required.

(i) ANSI Standard S1.4-1983, Specification for Sound Level Meters, including Amendment S1.4A-1985.

(ii) [Reserved]

(i) ASTM Specification B33-91, Standard Specifications for Tinned Soft or Annealed Copper Wire for Electrical Purposes.

(ii) [Reserved]

(i) TR-TSY-000008, Issue 2, August 1987, Digital Interface between the SLC 96 Digital Loop Carrier System and a Local Digital Switch.

(ii) Bell Communications Research (Bellcore) document TR-TSY-000057, Issue 1, April 1987, including Revision 1, November 1988, Functional Criteria for Digital Loop Carrier Systems.

(iii) Bell Communications Research (Bellcore) Document TR-NWT-000303, Issue 2, December 1992, including Revision 1, December 1993, Integrated Digital Loop Carrier System Generic Requirements, Objectives, and Interface.

(i) IEEE Standard 455-1985, Standard Test Procedure for Measuring Longitudinal Balance of Telephone Equipment Operating in the Voice Band.

(ii) [Reserved]

(i) RUS Bulletin 345-50, PE-60 (Sept 1979), RUS Specification for Trunk Carrier Systems.

(ii) [Reserved]

(i) The remote LC units shall operate satisfactorily with subscriber lines which meet all of the conditions under the bidder's specifications and all the requirements of this section. This section recognizes that the loop limit of the line concentrator is dependent upon the transmission facility between the LC central office termination and the LC remote unit. When voice frequency (physical) circuits are used, the loop limit from the COE to the subscriber shall be 1900 ohms (including the telephone set). When electronically derived circuits (carrier, lightwave, etc.) are used, the loop limits of the electronic system will control. The bidder shall identify the loop limits of the equipment to be supplied.

(ii) There should be provisions for such types of lines as ground start, loop start, regular subscriber, pay stations, etc.

(i) General. The line concentrator remote and central office terminal equipment shall satisfactorily transmit dialing information when used with subscriber dials having a speed of operation between 8 and 12 dial pulses per second and a break period of 55 to 65% of the total signaling period.

(ii) Subscriber dial interdigital time. The remote and central office LC equipment shall permit satisfactory telecommunications operation when used with subscriber rotary dial interdigital times of 200 milliseconds minimum, and pushbutton dialing with 50 milliseconds minimum.

(iii) Subscriber line pushbutton dialing frequencies. The frequency pairs assigned for pushbutton dialing when provided by the central office shall be as listed in this paragraph (f)(2)(iii), with an allowable variation of ±1.5 percent:

(i) When LC ringing is generated at the remote end, it shall be automatic and intermittent and shall be cut off from the called line upon removal of the handset at the called station during either the ringing or silent period.

(ii) When ringing generators are provided in the LC on an ancillary basis, they shall be accepted or technically accepted by RUS.

(iii) Where ringing is generated at the remote end, the ringing system shall provide sufficient ringing on a bridged basis over the voltage and temperature limits of this specification and over subscriber loops within the limits stated by the manufacturer. The manufacturer shall state the minimum number (not less than two) of main station ringers that can be used for each ringing option available.

(i) The minimum grade of service for traffic in the line concentrator shall be B =. 005 using the Traffic Table, based on the Erlang Lost-Calls-Cleared Formula. Required grade of service, traffic assumptions and calculations for the particular application being implemented shall be supplied by the bidder.

(ii) Service to customers served by a traffic sensitive LC should not be noticeably different than the service to customers served by the dedicated physical pairs from the central office so that uniform grade of service will be provided to all customers in any class of service. Reference § 1755.522(p)(1)(i), RUS General Specification for Digital, Stored Program Controlled Central Office Equipment.

(i) The system shall meet the following requirements:

(ii) Due to possible loss of the least significant bit on direct digital connections, a signal to distortion degradation of up to 2 dB may be allowed where adequately justified by the bidder.

(i) This paragraph (h)(20) covers the detailed requirements for the provision of interface units which will permit direct digital connection between the host central office and line concentrator subscriber terminals over digital facilities. The digital transmission system shall be compatible with T1 type span lines using a DS1 interface and other digital interfaces that may be specified by the owner. The RUS specification for the T1 span line equipment is PE-60. Other span line techniques may also be used. Diverse span line routing may be used when specified by the owner.

(ii) The output of a digital-to-digital port shall be Pulse Code Modulation (PCM), encoded in eight-bit words using the mu-255 encoding law and D3 encoding format, and arranged to interface with a T1 span line.

(iii) Signaling shall be by means of Multifrequency (MF) or Dual Pulsing (DP) and the system which is inherent in the A and B bits of the D3 format. In the case where A and B bits are not used for signaling or system control, these bits shall only be used for normal voice and data transmission.

(iv) When a direct digital interface between the span line and the host central office equipment is to be implemented, the following requirements shall be met:

(i) Adequate electrical protection of line concentrator equipment shall be included in the design of the system. The characteristics and application of protection devices must be such that they enable the line concentrator equipment to withstand, without damage or excessive protector maintenance, the dielectric stresses and currents that are produced in line-to-ground and tip-to-ring circuits through the equipment as a result of induced or conducted lightning or power system fault-related surges. All wire terminals connected to outside plant wire or cable pairs shall be protected from voltage and current surges.

(ii) Equipment must pass laboratory tests, simulating a hostile electrical environment, before being placed in the field for the purpose of obtaining field experience. For acceptance consideration RUS requires manufacturers to submit recently completed results (within 90 days of submittal) of data obtained from the prescribed testing. Manufacturers are expected to detail how data and tests were conducted. There are five basic types of laboratory tests which must be applied to exposed terminals in an effort to determine if the equipment will survive. Figure 2 of this section, Summary of Electrical Requirements and Tests, identifies the tests and their application as follows:

(iii) Electrical protection requirements for line concentrator equipment can be summarized briefly as follows:

(A) Current surge tests simulate the stress to which a relatively low impedance path may be subjected before main frame protectors break down. Paths with a 100 Hz impedance of 50 ohms or less shall be subjected to current surges, employing a 10 × 1000 microsecond waveshape as defined in Figure 3 of this section, Surge Waveshape. For the purpose of determining this impedance, arresters which are mounted within the equipment are to be considered zero impedance. The crest current shall not exceed 500A; however, depending on the impedance of the test specimen this value of current may be lower. The crest current through the sample, multiplied by the sample's 100 Hz impedance, shall not exceed 1000 V. Where sample impedance is less than 2 ohms, peak current shall be limited to 500A as shown in Figure 4 of this section, Current Surge Tests. Figures 3 and 4 follow:

(E) Arrester response delay tests are designed to stress the equipment in a manner similar to that caused by the delayed breakdown of gap type arresters when subjected to rapidly rising voltages. Arresters shall be removed for these tests, the peak surge voltage shall be the + 3 sigma breakdown voltage of the arrester in question on a voltage rising at 100 V per microsecond, and the time for the surge to decay to half voltage shall equal at least the delay time of the tube as explained in Figure 5 of this section, Arrester Response Delay Time as follows:

(iv) Tests shall be conducted in the following sequence. As not all tests are required in every application, non-applicable tests should be omitted:

(v) A minimum of five applications of each polarity for the surge tests and three for the 60 Hz Current Carrying Tests are the minimum required. All tests shall be conducted with not more than 1 minute between consecutive applications in each series of three or five applications to a specific configuration so that heating effects will be cumulative. See Figure 6 of this section, 60 Hz Current Surge Tests as follows:

(vi) Tests shall be applied between each of the following terminal combinations for all line operating conditions:

(i) Arresters shall be removed for all dielectric strength tests.

(ii) Direct current potentials shall be applied between all line terminals and the equipment chassis and between these terminals and grounded equipment housings in all instances where the circuitry is dc open circuit from the chassis, or connected to the chassis through a capacitor. The duration of all dielectric strength tests shall be at least 1 second. The applied potential shall be at a minimum equal to the plus 3 sigma dc breakdown voltage of the arrester, provided by the line concentrator manufacturer.

(i) All components shall be capable of being continuously energized at rated voltage without injury. Design precautions must be taken to prevent damage to other equipment components when a particular component fails.

(ii) Printed circuit boards or similar equipment employing electronic components should be self-protecting against external grounds applied to the connector terminals. Board components and coatings applied to finished products shall be of such material or so treated that they will not support combustion.

(iii) Every precaution shall be taken to protect electrostatically sensitive components from damage during handling. This shall include written instructions and recommendations.

(i) 6 turns of 30 gauge;

(ii) 6 turns of 26 gauge;

(iii) 6 turns of 24 gauge; or

(iv) 5 turns of 22 gauge.

(i) The bidder shall specify the environmental conditions necessary for safe storage and satisfactory operation of the equipment being bid. If requested, the bidder shall assist the owner in planning how to provide the necessary environment for the equipment.

(ii) To the extent practicable, the following temperature range objectives shall be met:

(i) When housed in a building supplied by the owner, a complete floor plan including ceiling height, floor loading, power outlets, cable entrances, equipment entry and travel, type of construction, and other pertinent information shall be supplied.

(ii) In order to limit corrosion, all metal parts of the housing and mounting frames shall be constructed of suitable corrosion resistant materials or materials protectively coated to render them adequately resistant to corrosion under the climatic and atmospheric conditions existing in the area in which the housing is to be installed.

(i) The line concentrator terminal equipment located at the central office shall be protected by the central office main distribution frame. The bidder may supply additional protection capability as appropriate. All protection devices (new or existing) shall be arranged to operate in a coordinated manner to protect equipment, limit surge currents, and protect personnel.

(ii) The distributing frame shall provide terminals for terminating all incoming cable pairs. Arresters shall be provided for all incoming cable pairs, or for a smaller number of pairs if specified.

(iii) The current carrying capacity of each arrester and its associated mounting shall coordinate with a #22 gauge copper conductor without causing a self-sustaining fire or permanently damaging other arrester positions. Where all cable pairs entering the housing are #24 gauge or finer, the arresters and mountings need only coordinate with #24 gauge cable conductors.

(iv) Remote terminal protectors may be mounted and arranged so that outside cable pairs may be terminated on the left or bottom side of protectors (when facing the vertical side of the MDF) or on the back surface of the protectors. Means for easy identification of pairs shall be provided.

(v) Protectors shall have a “dead front” (either insulated or grounded) where live metal parts are not readily accessible.

(vi) Protectors shall be provided with an accessible terminal of each incoming conductor which is suitable for the attachment of a temporary test lead. They shall also be constructed so that auxiliary test fixtures may be applied to open and test the subscriber's circuit in either direction. Terminals shall be suitable for wire wrapped connections or connectorized.

(vii) If specified, each protector group shall be furnished with a factory assembled tip cable for splicing to the outside cable; the tip cable shall be 20 feet (6.1 m) in length, unless otherwise specified. Tip cable used shall be RUS accepted.

(viii) Protector makes and types used shall be RUS accepted.

(i) The nominal operating voltage of the central office and remote terminal shall be 48 volts dc, provided by a battery with the positive side tied to system ground.

(ii) Where equipment is dc powered, it must operate satisfactorily over a range of 50 volts ±6 volts dc.

(iii) Where equipment is ac powered, it must operate satisfactorily over a range of 120±10 volts or 220±10 volts ac.

(i) Unless otherwise specified by the owner, sealed batteries shall be supplied for the remote line concentrator terminal.

(ii) The batteries shall have an ampere hour load capacity of no less than 8 busy hours. When an emergency ac supply source is available, the battery reserve may be reduced to 3 busy hours.

(iii) The batteries shall be sealed when they are mounted in the cabinet with the concentrator equipment.

(iv) When specified by the owner, battery heaters shall be supplied in a bidder-furnished housing.

(i) One charger capable of carrying the full dc power load of the remote terminal shall be supplied unless otherwise specified by the owner.

(ii) Charging shall be on a full float basis. The rectifiers shall be of the full wave, self-regulating, constant voltage, solid-state type and shall be capable of being turned on and off manually.

(iii) When charging batteries, the voltage at the battery terminals shall be adjustable and shall be set at the value recommended for the particular battery being charged, provided it is not above the maximum operating voltage of the central office switching equipment. The voltage shall not vary more than ±0.02 volt dc per cell between 10% load and 100% load. Between 3% and 10% load, the output voltage shall not vary more than ±0.04 volt dc per cell. Beyond full load current the output voltage shall drop sharply. The above output voltage shall be maintained with input line voltage variations of plus or minus 10 percent. Provision shall be made to manually change the output voltage of the rectifier to 2.25 volts per cell to provide an equalization charge on the battery.

(iv) The charger noise, when measured with a suitable noise measuring set and under the rated battery capacitance and load conditions, shall not exceed 22 dBrnC. See Figure 7 of this section, Charger Noise Test as follows:

(v) The charging equipment shall be provided with a means for indicating a failure of charging current whether due to ac power failure, an internal failure in the charger, or to other circumstances which might cause the output voltage of the charger to drop below the battery voltage. Where a supplementary constant current charger is used, an alarm shall be provided to indicate a failure of the charger.

(vi) Audible noise developed by the charging equipment shall be kept to a minimum. Acoustic noise resulting from operation of the rectifier shall be expressed in terms of dB indicated on a sound level meter conforming to American National Standards Institute S1.4, and shall not exceed 65 dB (A-weighting) measured at any point 5 feet (1.5m) from any vertical surface of the rectifier.

(vii) The charging equipment shall be designed so that neither the charger nor the central office equipment is subject to damage in case the battery circuit is opened for any value of load within the normal limits.

(i) Battery and charger control switches, dc voltmeters, dc ammeters, fuses and circuit breakers, supervisory and timer circuits shall be provided as required. Portable or panel mounted frequency meters or voltmeters shall be provided as specified by the owner.

(ii) Power panels, cabinets and shelves, and associated wiring shall be designed initially to handle the line concentrator terminal when it reaches its ultimate capacity as specified by the owner.

(iii) The power panel shall be of the “dead front” type.

(i) The equipment shall be completely wired and equipped with fuses, trouble signals, and all associated equipment for the wire capacity of the frames or cabinets provided.

(ii) Design precautions shall be taken to prevent the possibility of equipment damage arising from the insertion of an electronic package into the wrong connector or the removal of a package from any connector or improper insertion of the correct card in its connector.

(i) Trouble indications in the system may be displayed in the form of lights on the equipment units or printed circuit boards.

(ii) When required, a jack or other connector shall be provided to connect a fault or trouble recorder (printer or display).

(i) The maintenance system shall monitor and maintain the system operation without interruption of call processing except for major failures.

(ii) The maintenance system shall be arranged to provide the ability to determine trouble to an individual card, functional group of cards, or other equipment unit.

(i) Drawings of major equipment items such as frames, with the location of major component items of equipment shown therein;

(ii) Wiring diagrams indicating the specific method of wiring used on each item of equipment and interconnection wiring between items of equipment;

(iii) Maintenance drawings covering each equipment item that contains replaceable parts, appropriately identifying each part by name and part number; and

(iv) Job drawings including all drawings that are individual to the particular line concentrator involved such as mainframe, power equipment, etc.

(i) A complete index of required drawings;

(ii) An explanation of electrical principles of operation of overall concentrator system;

(iii) A list of tests which can be made with each piece of test equipment furnished and an explanation of the method of making each test;

(iv) A sample of each form recommended for use in keeping records;

(v) The criteria for analyzing results of tests and determining appropriate corrective action;

(vi) A set of general notes on methods of isolating equipment faults to specific printed circuit cards in the equipment;

(vii) A list of typical troubles which might be encountered, together with general indications as to probable location of each trouble; and

(viii) All special line concentrator system grounding requirements.

(i) Allow the bidder and its employees free access to the premises and facilities at all hours during the progress of the installation;

(ii) Provide access to the remote site and any other site for development work needed during the installation;

(iii) Take such action as necessary to ensure that the premises are dry and free from dust and in such condition as not to be hazardous to the installation personnel or the material to be installed (not required when remote terminal is not installed in a building);

(iv) Provide heat or air conditioning when required and general illumination in rooms in which work is to be performed or materials stored;

(v) Provide suitable openings in buildings to allow material to be placed in position (not required when a remote terminal is not installed in a building);

(vi) Provide the necessary conduit and commercial and dc-ac inverter output power to the locations shown on the approved floor plan drawings;

(vii) Provide 110 volts a.c., 60 Hz commercial power equipped with a secondary arrester and a reasonable number of outlets for test, maintenance and installation equipment;

(viii) Provide suitable openings or channels and ducts for cables and conductors from floor to floor and from room to room;

(ix) Provide suitable ground leads, as designated by the bidder (not required when remote terminal is not installed in a building);

(x) Provide the necessary wiring, central office ground and commercial power service, with a secondary arrester, to the location of an exterior remote terminal installation based on the voltage and load requirements furnished voltage and load requirements furnished by the bidder;

(xi) Test at the owners expense all lines and trunks for continuity, leakage and loop resistance and ensure that all lines and trunks are suitable for operation with the central office and remote terminal equipment specified;

(xii) Make alterations and repairs to buildings necessary for proper installation of material, except to repair damage for which the bidder or its employees are responsible;

(xiii) Connect outside cable pairs on the distributing frame (those connected to protectors);

(xiv) Furnish all line, class of service assignment, and party line assignment information to permit bidder to program the data base memory within a reasonable time prior to final testing;

(xv) Release for the bidder's use, as soon as possible, such portions of the existing plant as are necessary for the proper completion of such tests as require coordination with existing facilities including facilities for T1 span lines with properly installed repeaters between the central office and the remote terminal installations;

(xvi) Make prompt inspections as it deems necessary when notified by the bidder that the equipment, or any part thereof, is ready for acceptance;

(xvii) Provide adequate fire protection apparatus at the remote terminal, including one or more fire extinguishers or fire extinguishing systems of the gaseous type, that has low toxicity and effect on equipment;

(xviii) Provide necessary access ports for cable, if underfloor cabling is selected;

(xix) Install equipment and accessory plant devices mounted external to the central office building and external to the repeater and other outside housings including filters, repeater housings, splicing of repeater cable stubs, externally mounted protective devices and other such accessory devices in accordance with written instructions provided by the bidder; and

(xx) Make all cross connections (at the MDF or Intermediate Distribution Frame IDF) between the physical trunk or carrier equipment and the central office equipment unless otherwise specified in appendix A of this section.

(i) Allow the owner and its representatives access to all parts of the building at all times;

(ii) Obtain the owner's permission before proceeding with any work necessitating cutting into or through any part of the building structure such as girders, beams, concrete or tile floors, partitions or ceilings (does not apply to the installation of lag screws, expansion bolts, and similar devices used for fastening equipment to floors, columns, walls, and ceilings);

(iii) Be responsible for and repair all damage to the building due to carelessness of the bidder's workforce, exercise reasonable care to avoid any damage to the owner's switching equipment or other property, and report to the owner any damage to the building which may exist or may occur during its occupancy of the building;

(iv) Consult with the owner before cutting into or through any part of the building structure in all cases where the fireproofing or moisture proofing may be impaired;

(v) Take necessary steps to ensure that all fire fighting apparatus is accessible at all times and all flammable materials are kept in suitable places outside the building;

(vi) Not use gasoline, benzene, alcohol, naphtha, carbon tetrachloride or turpentine for cleaning any part of the equipment;

(vii) Be responsible for delivering the CO and remote terminal equipment to the sites where they will be needed;

(viii) Install the equipment in accordance with the specifications for the line concentrator;

(ix) Have all leads brought out to terminal blocks on the MDF (or IDF if stated in appendix A of this section) and have all terminal blocks identified and permanently labeled;

(x) Use separate shielded type leads grounded at one end only unless otherwise specified by the owner or bidder or tip cables meeting RUS cable crosstalk requirements for carrier frequencies inside the central office;

(xi) Group the cables to separate carrier frequency, voice frequency, signaling, and power leads;

(xii) Make the necessary power and ground connections (location as shown in appendix A of this section) to the purchaser's power terminals and ground bus unless otherwise stated in appendix A of this section (ground wire shall be 6 AWG unless otherwise stated);

(xiii) Place the battery in service in compliance with the recommendations of the battery manufacturer;

(xiv) Make final charger adjustments using the manufacturer's recommended procedure;

(xv) Run all jumpers, except line and trunk jumpers (those connected to protectors) unless otherwise specified in appendix A of this section;

(xvi) Establish and update all data base memories with subscriber information as supplied by the owner until an agreed turnover time;

(xvii) Give the owner notice of completion of the installation at least one week prior to completion;

(xviii) Permit the owner or its representative to conduct tests and inspections after installation has been completed in order that the owner may be assured the requirements for installation are met;

(xix) Allow access, before turnover, by the owner or its representative, upon request, to the test equipment which is to be turned over as a part of the delivered equipment, to permit the checking of the circuit features which are being tested and to permit the checking of the amount of connected equipment to which the test circuits have access;

(xx) Notify the owner promptly of the completion of work of the central office terminals, remote terminals or such portions thereof as are ready for inspection; and

(xxi) Correct promptly all defects for which the bidder is responsible.

(i) Two copies of the equipment list and the traffic calculations from which the quantities in the equipment list are determined;

(ii) Two copies of the traffic tables from which the quantities are determined, if other than the Erlang B traffic tables;

(iii) A block diagram of the line concentrator and associated maintenance equipment will be provided;

(iv) A prescribed method and criteria for acceptance of the completed line concentrator which will be subject to review;

(v) This special grounding requirements including the recommended configuration, suggested equipment and installation methods to be used to accomplish them;

(vi) The special handling and equipment requirements to avoid damage resulting from the discharge of static electricity (see paragraph (j)(4)(iii) of this section) or mechanical damage during transit installation and testing;

(vii) The location of technical assistance service, its availability and conditions for owner use and charges for the service by the bidder; and

(viii) The identification of the subscriber loop limits available beyond the line concentrator.

(i) All work shall be done in a neat, workmanlike manner. Equipment frames or cabinets shall be correctly located, carefully aligned, anchored, and firmly braced. Cables shall be carefully laid with sufficient radius of curvature and protected at corners and bends to ensure against damage from handling or vibration. Exterior cabinet installations for remote terminals shall be made in a permanent, eye-pleasing manner.

(ii) All multiple and associated wiring shall be continuous, free from crosses, reverses, and grounds and shall be correctly wired at all points.

(iii) An inspection shall be made by the owner or its representatives prior to performing operational and performance tests on the equipment, but after all installing operations which might disturb apparatus adjustments have been completed. The inspection shall be of such character and extent as to disclose with reasonable certainty any unsatisfactory condition of apparatus or equipment. During these inspections, or inspections for apparatus adjustments, or wire connections, or in testing of equipment, a sufficiently detailed examination shall be made throughout the portion of the equipment within which such condition is observed, or is likely to occur, to disclose the full extent of its existence, where any of the following conditions are observed:

(i) Operational tests shall be performed on all circuits and circuit components to ensure their proper functioning in accordance with appropriate explanation of the operation of the circuit.

(ii) All equipment shall be tested to ensure proper operation with all components connected in all possible combinations and each line shall be tested for proper ring, ring trip and supervision.

(iii) All fuses shall be verified for continuity and correct rating. Alarm indication shall be demonstrated for each equipped fuse position. An already failed fuse compatible with the fuse position may be used.

(iv) Each alarm or signal circuit shall be checked for correct operation.

(v) A sufficient quantity of locally originating and incoming calls shall be made to demonstrate the function of the line concentrator including all equipped transmission paths. When intra-link calling is supplied, all intra-link transmission paths shall be demonstrated.

(i) Data shall be supplied to the owner by the bidder in writing as a part of the final documents in closing out the contract as follows:

(ii) Data in the form of a checklist or other notations shall be supplied showing the results of the operational tests.

(iii) The bidder shall furnish to the owner a record of the battery cell or multicell unit voltages measured at the completion of the installation of the switching system before it is placed in commercial service. This is not required at a site where the owner furnishes dc power.

(i) The bidder shall notify the owner in writing at least one week before the date the complete system will be ready for inspection and tests. A joint inspection shall be made by the bidder and the owner (or owner's engineer) to determine that the equipment installation is acceptable. The inspection shall include physical inspection, a review of acceptance test data, operational tests, and sample measurements.

(ii) In the event that the measured data or operational tests show that equipment fails to meet the requirements quirements of this section, the deficiencies are to be resolved as set forth in Article II of the 397 Special Equipment Contract. (Copies are available from RUS, room 0174, U.S. Department of Agriculture, Washington, DC 20250-1500.) The reports of the bidder and the owner shall be detailed as to deficiencies, causes, corrective action necessary, corrective action to be taken, completion time, etc.