WPC 2BPZCourier 10cpi#|Jgx6X@87X@HP LaserJet IIIHPLASIII.PRSx  @,\EX@2R2 B ZD#|JHP LaserJet IIIHPLASIII.PRSx  @,\EX@HeadingChapter HeadingJ d  ) I. ׃  2t",Right ParRight-Aligned Paragraph Numbers>a݅@  I.   X(# BibliogrphyBibliography݅X  (# SubheadingSubheading0\ E A.  "^'`8,,`2ptk#HHH,H H@7@ j$Y//,lYL p?7L(4)  `PWR(4)xxhED(7) y.Xxdddy 011 Y   yxdddy    yO. #\\  PRu\P#APage `(#kFile: 11AP16K   XX [p ` #\  PButHP#JULY 1991`(#_DOC.: IEEE P802.11/91    yxbdddy 3b_  yxXdddy    yO. #\\  PRu\P#Revised: July 2, 1991APage `x(#^Access Protocol IIRypinski3  #2P'P#> IEEE P802.11 ă +802 LAN Access Method for Wireless Physical Medium    #Xl2P0kXP#yxZdddy  R  DATE: ` ` June 22, 1991`(#c REVISED: July 2, 1991    l yx dddy  Pi  TITLE: ` ` ACCESS PROTOCOL FOR IVD WIRELESS LANPART II  ; yxu dddy  R4  4 l  AUTHOR: ` ` Chandos A. Rypinski, ` `  (Chief Technical Officer ` ` LACE, Inc.`(#aTelephone: 707 765 9627 ` ` 921 Transport Way`-(#`Facsimile: 707 762 5328 ` ` Petaluma, California 94954 USA   yxRdddy #\2PP# SUMMARY Work continues on the previous contribution of the same title (P802.11/9119 last revised 22191) which retroactively becomes Part I of a series. A short summary of the main changes and current Message/Field List is given, and it is intended that a revised and updated document will be prepared for a later meeting. The main purposes of the changes now reported are provisions for a system identifier and for multiple channel and site operation as might be obtained either by frequency or time division or code set separation with direct sequence spread spectrum modulation. Table of Contents`!(#uPageă   XSUMMARY p`"(#v 1 XDESCRIPTION OF CHANGES p`"(#v 1 XFIELDS AND ACRONYMS p`"(#v 2 XX` ` Preamble and Delimiters ` p`"(#v 2 XX` ` Address Fields ` p`"(#v 2 XX` ` Identifiers ` p`"(#v 2 XMESSAGE FORMATS p`"(#v 2 XTABLE I ACRONYM DEFINITION p`"(#v 2 XTABLE II MESSAGE FRAME FORMATS WITH FIELD ASSIGNMENTS p`"(#v 3 A! .@+@+::  І 3THIS PAGE LEFT BLANK INTENTIONALLY .@+@+::   \ . ACCESS PROTOCOL FOR IVD WIRELESS LANPART II ă #\2PP# SUMMARY  Work continues on the previous contribution of the same title (P802.11/9119 last revised 22191) which retroactively becomes Part I of a series. A short summary of the main changes and current Message/Field List is given, and it is intended that a revised and updated document will be prepared for a later meeting. The main purposes of the changes now reported are provisions for a system identifier and for multiple channel and site operation as might be obtained either by frequency or time division or code set separation with direct sequence spread spectrum modulation. DESCRIPTION OF CHANGES  A number of purposes have been served by the changes listed as follows: 1.The new fields used are as follows: ` ` SYS (=0system identifierHppQ1 octet ` ` CHL (=0code/channel identifierHppQ4 bits ` ` PWR (=0station power level setHppQ4 bits ` ` CNN (=0connection/session no.HppQ4 bits ` ` SGN (=0segment counter/circuit statusppQ8 bits 2.XThe definitions of packet data frames have been adjusted so that Packets or the first segment or a segmented packet use long address in one message type and segments always use short address in another message type for accesspoint originate. Packet and segment data frames are different types in stationoriginate messages both using short address.(# 3.XInvitationtorequest has added the channel identifier on which the message will be transferred if a Request is received. This is primarily to reduce the time in which the setup channel is occupied by moving Grant to a data transfer channel, while still allowing an inrange peer station to hear the peer Request message knowing on which channel it will be transferred.(# 4.XThe Nchannel Power Set message has been created to give the Accesspoint the capacity to preset a Station to required values to receive a message on a data transfer channel. There are a few other circumstances in which the message is useful.(# 5.XIt is assumed that a Station could maintain more than one simultaneous connection which would make the short address ambiguous as a segment label. This is resolved with a CNN field.(# 6.XNack and Nack Repeat are merged to open a type for the Set message.(# 7.XPoll and Invitationtoregister are merged. The invitation is marked by a null destination address. The Invitationtoregister function is deleted from the Invitationtorequest message.(# 8.The new fields have been added in the messages where they are appropriate and useful. 9.XAn effort has been made to regularize the length of messages and the position of fields in the different messages so that in most cases they occur at the same point. Where this condition cannot be met, then they are in the same sequence. To a small degree position regularity and brevity of message cannot be achieved at the same time.(# 10.XThe Grant message contains the CHL and PWR fields so that it can be sent on the setup channel to enable Segments to be sent on the allotted data transfer channel.(# (.@+@+:: 6 TABLE I ACRONYM DEFINITION ׃ ACRONYM` ` DEFINITION`0(#kLENGTH IN BITSă API= ` ` accesspoint identifier `"(#x4 CHL= ` ` assigned channel identifier`"(#x4 CNN=` ` connection number identifier`"(#x4 CRC= ` ` cyclic redundancy check `!(#r4 or 16 DA= ` ` destination address `(#jeither 16 or 64 DIR= ` ` direction bit and ` ` 1st digit of message type identifier`"(#x1 ED= ` ` end delimiter using 7bit Barker`"(#x7 LEN= ` ` length of PDU in octets (see note)`x"(#w12 NUL=` ` nullno assigned meaning PDU= ` ` packet data unit (payload) `H(#efrom 0 to 288 octets PRE= ` ` preamble `@"(#v 15 PWR= ` ` power set command `"(#x4 SA= ` ` source address `(#jeither 16 or 64 SD= ` ` start delimiter using 7bit Barker`"(#x7 SGN=` ` segment counter/circuit status`"(#x8 SID= ` ` service type identifier`"(#x4 SYS= ` ` system identifier`"(#x8 TYP= ` ` 2nd and 3rd digits of message type identifier`"(#x4 FIELDS AND ACRONYMS Message frames are divided into fields, one of which may be a variable length data payload. Some of the fields are necessarily passed in and out of the physical layer. The acronyms for these fields are listed and defined in Table I above. Further detail on some of these is given below. Preamble and Delimiters The preamble pattern is chosen to facilitate bit clock acquisition after which the 7bit Barker or start delimiting can be recognized. The end delimiter is an inverted 7bit Barker which backs up the primary delimiting by the LEN field. Address Fields Long addresses are generally used. The short address is local and internal, and is used for labeling of segments for long packets and virtual circuits. CNN is used to identify multiple simultaneous connections at one Station. The long address is 8 octets even though the LAN global address is defined as only 6 octets. Telecom global addressing, as defined in the CCITT E.164 is 15 decimal digits coded BCD (60 bits). In the IEEE 802.6 integrated voice data Wide Area Network standard, both of these types of addresses are enclosed in an 8 octet field with 4 bits used for differentiation and detail definition. The allocation for long address in this access protocol exactly emulates this developing standard practice. The added two octets in the long address is a specific accommodation of global addressing in voice data integration. Identifiers The source of the signal is given for the accesspoint in the API field which is repeated back by the Station in setup messages. The API is a location identifier within a pattern. The SYS field is a further system identifier which is used when independently managed systems have overlapping radio coverage. One system will generally ignore received transmissions that do not have the correct SYS field. The service type identifier, SID, marks Request messages for connectiontype services or datagrams. MESSAGE FORMATS Message formats using these fields are shown in Table II following. AO and SO indicate Accesspoint originate or Systemoriginate.(.@+@+:: 3'3'Standard'3'3StandardHPLASIII.PRSx  XX  XX  XXXX #\2PP#,> TABLE II MESSAGE FRAME FORMATS WITH FIELD ASSIGNMENTS ׃  `  PACKET DIRECTION/TYPE AND FUNCTION DESCRIPTION FIELDS USED `,,81 Message Length ă #H H@7 @#|As noted|1` ` | (|20|hh8|3@|H|4ppQ|Y|5  a|xxi|6 q|(#(#y|7%%|''|80*0*|,,|9 y.Xpdddyy.Xdddy 0$ yXdddy 001AOSegment data frameshort address `@/8110+PDU y81dddyڃ PRE(15)SD(7) DIR(1) (TYP(4)0CNN(4)hh8DA(16)@HppQYSGN(8) PDU 0288 octsCRC16(16) (0hh8ED(7) y.Xdddy 003AOPacket data framelong address `@/8125+PDU PRE(15)SD(7) DIR(1) (TYP(4)0API(4) DA(64) SA(64)SID(4)` ` LEN(12) PDU 0288 octsCRC16 (16) (0hh8ED (7) y.X@ dddy 005AOInvitationtorequest `0818 PRE (15)SD(7) DIR(1) (TYP(4)0API(4)hh8SYS(8)@HNUL (8)ppQYCHL(4)  aNUL(4)xxiED(7) y.X dddy 007AOPoll or invitationtoregister `0818 PRE(15)SD(7) DIR(1) (TYP(4)0API(4)hh8DA(16)@HppQYSYS(8)   axxiED(7) y.Xdddy 009AOSet ChannelN or CodeN or PWR `0818 PRE(15)SD(7) DIR(1) (TYP(4)0API(4)hh8DA(16)@HppQYCHL(4)  aPWR(4)xxiED(7) y.Xxdddy 011AOAck `0818 PRE(15)SD(7) DIR(1) (TYP(4)0API(4)hh8DA(16)@HppQYCHL(4)  aPWR(4)xxiED(7) y.Xdddy 013AONackrepeat `0818 PRE(15)SD(7) DIR(1) (TYP(4)0API(4)hh8DA(16)@HppQYCHL(4)  aPWR(4)xxiED(7) y.XHdddy 015AOGrant ` ` (DA=requesting station)`0819 y.Xdddyy.Xdddy PRE(15)SD(7) DIR(1) (TYP(4)0API(4)hh8DA(16)@HppQYCHL(4)  aPWR(4)xxiCNN(4) qCRC(4)(#(#ySGN(8)%%''ED (7)  d$  100SOSegment data frameshort address `@/8110+PDU PRE(15)SD(7) DIR(1) (TYP(4)0CNN(4)hh8DA(16)@HppQYSGN(8) PDU 0288 octsCRC16(16) (0hh8ED (7) y.Xdddy 102SORegister ``08113 PRE(15)SD(7) DIR(1) (TYP(4)0API(4) SA(64)ED(7) y.X dddy 104SODeregister ``08113 PRE(15)SD(7) DIR(1) (TYP(4)0API(4) SA(64)ED (7) y.X(dddy 106SORequestshort address ``08111 PRE(15)SD(7) DIR(1) (TYP(4)0CNN(4)hh8DA (16)@HppQYSA (16)  axxi q(#(#ySID(4)%%LEN(12)''0*0*,,ED (7) y.Xdddy 108SORequestlong address ``08123 PRE(15)SD(7) DIR(1) (TYP(4)0CNN(4) DA(64) SA(64)SID(4)` ` LEN (12)0hh8ED (7) y.X`dddy 110SOAck `0817 PRE(15)SD(7) DIR(1) (TYP(4)0API(4)hh8SA (16)@HppQYED (7) y.Xdddy 112SONack `0817 PRE(15)SD(7) DIR(1) (TYP(4)0API(4)hh8SA (16)@HppQYED (7) y.X0!dddy 114SOPacket data frame `@/8110+PDU PRE(15)SD(7) DIR(1) (TYP(4)0CNN(4)hh8DA (16)@HppQYSGN(8) y.XL#dddyy.Xp#dddyPDU 0288 octsCRC16 (16) (0hh8ED (7) # \\  PRu\P#Revised: July 2, 1991VPage `,81File: 11AP16K