Abstract:
A method of activating a mobile station for communicating with a telecommunications network, the method encompassing a two-stage registration procedure whereby in the first registration procedure, a permanent mobile station ID is obtained by the mobile station and in the second registration procedure, the permanent mobile station ID is used to identify the mobile station when downloading programming data from the telecommunications network. The invention allows for programming the mobile station with a permanent MSID of either a MIN or IMSI format, without requiring a TIA/EIA-136 SPACH notification process to notify the MS of incoming programming data. In particular, the steps of the method comprise: receiving at the telecommunications network a temporary activation ID from a mobile station; the network verifying the temporary activation ID; the network communicating a permanent MSID to the mobile station; the network receiving a permanent MSID from the mobile station; the network verifying the permanent MSID and then downloading programming data to the MS.

Description:
BACKGROUND 
     1. Field of the Invention 
     The present invention relates generally to wireless communications, and more particularly, to a method for programming a mobile station using a permanent mobile station identifier which is programmed into the mobile station before provisioning data is downloaded to the mobile station. 
     2. Description of the Prior Art 
     North American cellular telecommunications networks traditionally operate in two frequency bands (A and B) in the 800-MHz hyperband. The most recent evolution in cellular telecommunications involves the adoption of six additional frequency bands (A-F) in the 1900-MHz hyperband for use in handling mobile and personal communications. The 1900-MHz hyperband is also known as the Personal Communication Services (PCS) hyperband. Frequency bands within the 800-MHz hyperband and the 1900-MHz hyperband are defined in EIA/TIA Standard IS-136, which is hereby incorporated by reference herein. Other standards which define cellular telephone operations in North America include EIA-627, EIA-553, and the intersystem signaling standard IS-41 which are also incorporated by reference herein. Each of the frequency bands specified for the cellular and PCS hyperbands is allocated a plurality of voice or speech channels and at least one access or control channel. The control channel is used to control or supervise the operation of mobile stations by means of information transmitted to and received from the mobile stations. Such information may include, but is not limited to, incoming call signals, outgoing call signals, page signals, page response signals, location registration signals, voice channel assignments, maintenance instructions, short message service (SMS) messages, and cell selection or reselection instructions as mobile stations travel out of the radio coverage of one cell and into the radio coverage of another cell. The voice channel is used to carry subscriber telephonic communications as well as messages requesting mobile station assistance in making hand-off evaluations. The control and voice channels may operate in either an analog mode or a digital mode. 
     In existing TIA/ELA-136 Over-the-Air Service Provisioning procedures, a mobile station is identified during the initial activation process by an Activation Mobile Identification Number (“Activation MIN”) or “Dummy MIN.” In TIA/EIA-136 systems, a Mobile Station ID (“MSID”) is utilized to distinguish the mobile station being programmed from other mobile stations during messaging and paging processes, including the downloading of programming information to the mobile station. The MSID is typically a MIN of the type widely used in existing systems, or an International Mobile Station Identity (“IMSI”) of the type used in GSM systems. A mobile station fresh out of the factory does not have the permanent MSID programmed into its memory. The “Real MIN”, “Real IMSI”, or both, is typically not programmed into the mobile station until all provisioning information is downloaded, and the mobile station has received a “Commit” message from the provisioning platform. Accordingly, it is the Activation MIN that is used as a temporary MSID to identify the mobile station when provisioning information is downloaded to the mobile station. 
     The rapid increase in wireless customers has caused drawbacks with this procedure. The large number of mobile stations in the marketplace makes it very likely for different mobile stations to request simultaneous activation using the same “temporary MSID.” The duplication of temporary MSIDs can result in one mobile station receiving programming data intended for another mobile station, and the erroneous programming resulting in one or both of the mobile stations being incorrectly activated or not activated at all. 
     An example of a prior art activation method is disclosed in U.S. Pat. No. 5,603,084 to Henry Jr., et al. The Henry patent describes a cellular telephone that includes a programmable memory location that is remotely programmed with a unique temporary identification number. The telephone provides the temporary identification number to the cellular network, which establishes a page to the telephone using the temporary identification number as the phone ID. Data, including a permanent MSID, is transmitted during the page and the programmable memory is programmed with the MSID. 
     U.S. Pat. No. 5,956,636 to Lipsit discloses a method for remotely activating a wireless device, which has been fully programmed prior to the activation procedure. Activation of the device includes the steps of placing a call with the device and determining the MIN using caller ID. The system prompts the user to enter a predetermined security code into the device. If this security code originates from the same device as the detected MIN, the device is then activated. 
     U.S. Pat. No. 6,014,561 to Mölne discloses a method for Over-the-Air Activation of a radio telephone. In this system, when a new subscriber places a new call, the system receives the IMSI number and transfers the IMSI to a customer service center. An employee searches a database for previously received and stored activation information. A telephone number is then assigned to the subscriber. The telephone number and previously stored information is subsequently assigned to the subscriber, and the telephone number and activation information are stored in a customer service database. 
     U.S. Pat. No. 5,297,192 to Gerszberg discloses a method and apparatus for remotely programming mobile data into a mobile data telephone. This patent teaches downloading Number Assignment Module (“NAM”) designation parameters to a mobile unit to allow service authorization codes and activation to be entered remotely. A cellular mobile customer initially calls a remote cellular system center to establish a voice communication channel between the mobile unit and the system center. A modem associated with the mobile unit is selectively bridged onto the voice communication channel for data transfer between a data source disposed at the remote center and the modem. 
     U.S. Pat. No. 5,301,223 to Amadon, et al. describes an apparatus and method for use in a mobile telephone rental system. Credit card information is communicated between the mobile unit and a Voice Response System for customer registration and remote programming of the mobile unit functions and NAM settings. Data from the mobile unit is transmitted in variable length, encrypted and error protected Packet Data Units. 
     SUMMARY OF THE INVENTION 
     In view of the above, it is an object of the present invention to provide an improved method for programming a mobile station using a permanent MSID. 
     It is another object of the present invention to provide a method for programming a permanent MSID into the mobile station prior to communicating programming data from the network. 
     It is still another object of the present invention to program a permanent MSID of either a MIN or IMSI format without requiring a TIA/EIA-136 SPACH notification process to notify the mobile station of incoming programming data. 
     It is yet another object of the present invention to provide a method for programming a mobile station in which a Home Location Register (“HLR”) that will ultimately serve the mobile station, performs the mobile management functions during the activation process. 
     It is still another object of the present invention to provide a method for programming a mobile station which reduces the likelihood of conflict between an Activation MIN used by an unprogrammed mobile station and a real MSID associated with an activated or another unactivated mobile station. 
     It is yet another object of the present invention to provide a method for programming a mobile station which prevents programming interruption caused by conflicting Activation MINs and real MSIDs. 
     It is still another object of the present invention to provide a method for programming a mobile station which permits allocation of more channels and prioritizing the voice traffic over data so that the voice service is unaffected by the registration processes, even during periods of peak demand. 
     In accordance with the above objects and additional objects that will become apparent hereinafter, the present invention provides a method of activating a mobile station for communicating with a telecommunications network. The method encompasses a two-stage registration procedure whereby: (1) the mobile station obtains a permanent MSID from the network; and (2) the permanent MSID is communicated to the network to identify the mobile station to enable provisioning information to be downloaded to the mobile station. Initially, a subscriber contacts the wireless carrier and supplies subscription information, including the phone type and Electronic Serial Number (“ESN”). Upon power-up, the mobile station sends a registration request message over a Digital Control Channel (“DCC”) to the network including a temporary activation MSID (MIN or IMSI), and ESN of the mobile station. The registration request message is received at the Mobile Switching Center (“MSC”) in the network. Upon receipt, the MSC sends a registration notification message containing the activation MSID and ESN to an Over-the-Air Activation Function (“OTAF”). The network verifies whether the activation MSID is associated with the mobile station based upon the subscription information and, if verified, the OTAF sends a registration notification message containing the permanent MSID to the MSC. This permanent MSID is then communicated over the network to the mobile station, which stores the permanent MSID in NAM or SIM memory. 
     During the second part of the registration process, the permanent MSID and ESN are communicated from the mobile station to the MSC over the DCC. The MSC then sends a registration notification message to an HLR assigned to the permanent MSID. The HLR verifies the mobile station and sends a registration notification message to the MSC, acknowledging receipt of the registration notification message. The MSC then communicates a registration accept message to the mobile station. The HLR sends a message to the OTAF including the permanent MSID, ESN and address of the MSC where the mobile station is registered, requesting that the remaining programming information be sent to the mobile station. The OTAF acknowledges the request to the MSC, and sends programming data to the MSC identified by the HLR. The MSC then sends a SPACH notification of programming data on the digital control channel to the mobile station. Upon successful receipt, the mobile station sends a SPACH confirmation to the MSC. The MSC then downloads the programming data to the mobile station. Upon completion, the mobile station acknowledges receipt of the programming data to the MSC, and the MSC notifies the activation center of a successful download of programming data to the mobile station. 
     This two-stage registration procedure reduces the likelihood of conflicting activation M[Ns by using the real MSID to identify the mobile station to which the programming data is being downloaded. 
     The present invention will now be described with particular reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic of a representative wireless communications system; 
         FIG. 2  is a schematic of relevant components of the wireless communications system for implementing the method for programming a mobile station in accordance with the invention; 
         FIG. 3  is an illustrative schematic of a mobile station; 
         FIGS. 4A-4C  depict a flowchart sequence for programming a mobile station in accordance with the invention; and 
         FIG. 5  is an operational flow diagram of the programming method shown in FIGS.  4 A- 4 C. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference now to the drawings,  FIG. 1  depicts a representative wireless communications system (“WCS”)  10 . The WCS  10  serves a number of wireless mobile stations (“MS”)  12   A-F  and wireline terminals (not shown) within a geographic area partitioned into a plurality of spatially distinct regions called “cells”  14   A-C . Each cell  14  includes a respective base station (“BS”)  16   A-C , and a boundary represented by an irregular shape that depends on terrain, electromagnetic sources and many other variables. The mobile stations communicate via one or more wireless access technologies (e.g., TDMA, CDMA, FDMA, etc.), providing one or more services (e.g., cordless, cellular, PCS, wireless local loop, SMR/ESMR, two-way paging, etc.) with signals representing audio, video, data, multimedia, etc. Each BS  16  preferably conforms to the IS- 56 B standard, and communicates with a Mobile Switching Center (MSC)  18 , also known as a mobile telephone switching office, in accordance with well-known standards. The MSC  18  is interconnected with local switching offices (“LSO”)  20   AB  that access wireline terminals, and a toll switching office (“TSO”)  22 , which interconnects the LSOs  20  and MSC  18  with other LSOs and wireless switching centers (indicated by the arrows in FIG.  1 ). The MSC  18  has several functions, including routing or “switching” calls between wireless communications terminals or base stations or, alternatively, between a wireless communications terminal and a wireline terminal accessible to a MSC  18  through LSOs  20  and/or TSO  22 . 
     Referring now to  FIG. 2 , there is depicted a representative illustration of select components and communications links within the WCS  10  shown in FIG.  1 . The MSC  18  interfaces through bidirectional communication with a subscription activation system  19 . The subscription activation system  19  includes a home system comprising a Home Location Register (“HLR”)  24  and an Over-the-Air Activation Function (“OTAF”)  26 , and a Provisioning Server (“PS”)  28 . The PS  28  is the location where customer-service personnel receive activation calls and engage in voice conversations with customers pertaining to the connections to customer mobile stations. The PS  28  may interface with an interactive voice response unit (“IVRU”), not shown, of the type known in the art to handle customer calls. The PS  28  is also the location where the carrier assigns the mobile station ID to the MS  12 , and is the system component responsible for populating subscription information in the carrier&#39;s network equipment, including HLR  24 . The HLR  24  and the PS  28  contain configuration and security data for the MS  12 . The purpose of the HLR  24  is to keep track of a specific, predetermined group of mobile stations, wherever they may move, and to provide a telephone number to routing address mapping. The OTAF  26  generates the permanent MSID, and subsequent programming information for the MS  12  in a teleservice message to the MSC  18  as will be discussed further hereinbelow. The MSC  18  is also connected to a Visitor Location Register (“VLR”), not shown, which stores and maintains information on subscribers from other home systems which are roaming within the present system. 
     The subscription activation system  19  includes at least one MS/customer database  21 . The MS/customer database  21  contains the preprogrammed Electronic Serial Number (“ESN”) and Mobile Identification Number (“MIN”) or International Mobile Station Identity (“IMSI”) number of the MS, the MIN or IMSI of the SIM card associated with the MS  12 , and other information accessed by the PS  28  using the MSID. The ESN is the unique telephone serial number stored in the memory of each MS  12  during manufacture, and is used to identify the manufacturer and model of the MS  12 . The ESN is an 11 digit number required by the FCC and is used in combination with the MIN during the registration procedure described below. The MIN is commonly used in existing systems and the IMSI is widely used in GSM systems. The MS/customer database  21  is used for storing activation information that is later transferred by the activation system  19  to the customer database  23  of the home system of the subscriber. Each MS  12  can be identified by the WCS  10  by data stored in memory locations in the MS. The programmable memory  32  contains the unique MIN or IMSI assigned by the cellular system. In existing TIA/EIA-136 Over-the-Air Service Provisioning procedures, an “Activation MIN” or “Dummy MIN” is used to identify the MS during the initial activation process. In TIA/EIA-136 systems, the Mobile Station ID (“MSID”) is used to identify and distinguish the MS  12  being programmed from other mobile stations during messaging and paging processes, including the delivery of programming information. 
     With reference to  FIG. 3 , a representative MS  12  includes a processor  30 , programmable memory  32 , and non-programmable or read only memory (“ROM”)  34 . The MS  12  includes a conventional input keypad  36 , a microphone  38 , and a speaker  40 . The MS  12  may include a Subscriber Identity Module (“SIM”) card  35  for storing information for operation of the MS  12  in both PCS and conventional AMPS communications systems. The MS  12  can also include an “AMPS” memory (part of programmable memory  22 ) for controlling operation of the MS  12  when the AMPS (cellular frequency band) mode is selected. The SIM card  35  is connected to the processor  30  for retrieval of the appropriate information as required depending upon which type of system the MS  12  is communicating within. SIM cards are described more fully in the Specification of the Subscriber Identity Module-Mobile Equipment (SIM-ME) interface (GSM 11.11) by ETSI, which is hereby incorporated by reference. A transceiver  42  enables communication signals to be transmitted to and received from a BS  16  via an antenna  44  over the wireless communication path indicated generally at  46 . The processor  30  operates under stored program control and coordinates the operation of the transceiver  42  in the MS  12  and provides an interface between the other elements of the MS  12  as is well known in the art. The processor  30  inserts and extracts control messages, changes physical parameters such as channel frequencies, mode of operation, frequency band, and the like. 
     The processor  30  preferably includes a memory programming function for programming the programmable memory  32  in response to the receipt of a REGISTRATION_ACCEPT (Real MIN) from the MSC  18 . This enables the MS  12  to be activated or programmed remotely in response to communication signals generated by the WCS  10 . The communication signals may be transmitted from the WCS  10  in a page format to the transceiver  42  of the MS  12 . The page preferably comprises a Short Message Service (“SMS”) data string provided on a Digital Control Channel (“DCC”) according to the TIA/EIA IS-136 standard. In this connection, the SMS data string may include up to 239 octets (or bytes) which can be formatted as characters of alphanumeric data. 
     Referring now to  FIGS. 4A-4C  and  5 , depicted are a flow chart and operational flow diagram, respectively, of a representative method for implementing the programming function in accordance with the present invention. In  FIG. 5 , the vertical axis represents time and the horizontal axis represents operational flow. Generally, the method involves first and second registration procedures whereby during the first registration, the network assigns and provides a permanent MSID to the MS  12 . During the second registration, the MS  12  identifies itself with the permanent MSID and programming data (provisioning information) is downloaded to the MS  12 . In this manner, the permanent MSID is stored in the MS  12  prior to the data download procedure. 
     The activation process is initiated when a customer/subscriber calls the carrier&#39;s activation center within the subscription activation system  19 . At block  48  (FIG.  4 A), the subscriber supplies subscription information to the carrier, including phone type and ESN. This information is stored in the MS/customer database  21 . 
     At block  50 , the carrier&#39;s PS  28  generates a subscription for the subscriber, assigns a permanent mobile station ID (“PERM_MSID”) to the BS  12  and a directory number used to call that phone. The PERM_MSID is either in the MIN or IMSI format. The PERM_MSID is stored in the MS/customer database  21  along with the applicable subscription information. 
     At block  52 , the subscription information is populated in the carrier&#39;s network equipment, and PERM_MSID is communicated to HLR  24 , where it is stored in a home system database  23 . At this time, Number Assignment Module (“NAM”) provisioning data, information intended to be stored in the MS specific to the mobile subscriber, is sent to the OTAF  26  with subscription related parameters to be programmed into the MS  12  at block  54 . The provisioning record is identified by the ESN of the MS  12  sent to the OTAF  26 . NAM parameters include the Public Service ID (“PSID”), the Residential Service ID (RSID”), etc. The NAM is part of the Short Message Service (“SMS”) data string, which may include up to 293 characters originating from the PS  28  and transmitted from the BS 16 20 according to the TIA/EIA IS-136 standard. Exemplary NAM parameters may be listed as follows: 
                                             Parameter   Example                           ESN   15503124387           MIN   411-034-2112           Access Overload Class   015           Group ID   10           Security Code   73844           Group ID Mark   10           Initial Paging Channel   444           Secondary Paging Channel   805           Wake Up Message   AT&amp;T Wireless Services           Lock Code   144                        
For the NAM parameters listed above, the ESNs are stored as binary representations, but are typically displayed in either hexadecimal or decimal format. ESNs displayed in decimal format are displayed as eleven digit numbers, where the first three digits are called the manufacturers prefix and indicate the manufacturer of the MS.
 
     As discussed above, the memory  32  of the MS  12  is programmed by the manufacturer with an initial activation number. The initial activation number such as a MIN or IMSI may also include predetermined digits chosen from the ESN, such as, for example, the least significant  10  digits of the ESN. After the subscriber powers up the MS  12  at block  56 , a first wireless communication is established between the MS  12  and the WCS  10  at block  58 . In this connection, the transceiver  42  may have an activation function for establishing a wireless communication from the MS  12  to the WCS  10  before the telephone is programmed. This activation function allows the transceiver  42  to transmit the temporary ACTIVATION_MSID (MIN or IMSI) to the system. The WCS  10  uses the ACTIVATION_MSID to initially identify the MS  12  during the first registration after an account has been set up as discussed above. The activation function can be initiated by manually dialing a dedicated telephone number from the MS  12 , or such communication can be automatically initiated by the MS  12  upon initial power up. For example, a set variable in programmable memory  32  can be used to indicate whether the MS  12  has been programmed or is in an unprogrammed state. If the variable indicates that the MS  12  has not been programmed, the MS  12  automatically establishes a wireless communication to the network using a previously stored activation number to initiate the activation process when turned on or when the send button is pressed. If the activation process is initiated by the MS  12 , the transceiver  42  may also include an information function allowing the MS  12  to transmit information requested by the cellular system. This information may include account information such as billing information, service information, the user&#39;s name, the user&#39;s address, credit information, and other user information. This information may be supplied to the transceiver through either the keypad  40  or microphone  42 . The MS  12  finds the appropriate service provider and sends the ACTIVATION_MSID in the form of a REGISTRATION(ACTIVATION_MIN, ESN) to MSC  18  on a DCC. This registration message enables the MSC  18  to uniquely identify the MS  12  during the first registration process. 
     At block  60 , the MSC receives REGISTRATION (ACTIVATION_MIN, ESN) from MS  12 , and identifies ACTIVATION_MSID (ACTIVATION_MIN). The MSC  18  then routes a registration notification message REGNOT(ACTIVATION_MSID, ESN) to the HLR/OTAF. At block  62 , the OTAF  26  receives the registration and confirms that the ESN passed in the registration corresponds to data stored in the OTAF&#39;s programming database. The OTAF searches for a record waiting to be programmed into the MS  12  corresponding to the ESN supplied from that MS  12 . The OTAF locates the PERMANENT_MSID assigned to the MS  12 , formats a registration acknowledgment REGNOT(REAL_MSID)) representing the real MSID for the MS  12 , and sends REGNOT(REAL_MSID) to MSC  18 . 
     At block  64 , the MSC  18  receives the registration acknowledgement, and sends a registration accept message REG_ACCEPT(REAL_MIN) to MS  12  over a DCC via communication path  46 . The MS  12  receives REG_ACCEPT, and stores REAL_MIN in NAM  37  or SIM  35  programmable memory  32 , thereby overwriting the ACTIVATION_MIN at block  66 . This completes the first registration process which provides the MS  12  with a permanent MSID. 
     The second registration is initiated at block  66  when the MS  12  sends a new registration message, REGISTRATION(REAL_MSID, ESN), to MSC  18  over a DCC. The MSC  18  routes a registration notification message REGNOT(REAL_MSID, ESN) to the HLR  24  assigned to the permanent MSID at block  68 . The HLR  24  then sends an acknowledgement message REGNOT(REAL_MSID) to the MSC  18  that issued the request at block  70 . The MSC  18  sends a registration accept message REG_ACCEPT(REAL_MIN) to the MS  12  at block  72 , signaling the MS  12  that it is now ready to receive programming data from the WCS  10 . The data download process is initiated with the HLR  24  sending a notification to the OTAF  26  to send programming information to the MS  12 . The message may be formatted in terms of an SMS data string discussed above. At block  74 , the HLR  24  sends a data download request message SMSREQ(MSID, ESN, SMSTID, SMSADDR) to OTAF  26 . This information includes the permanent MSID, the ESN, and the address of the MSC  18  (SMSTID, SMSADDR) where the MS  12  is registered. The OTAF  26  acknowledges the request, SMSNOT, at block  76 . The OTAF  26  then sends the programming information in a teleservice message(s) to the serving MSC  18  identified by HLR  24  in the form SMSREQ[MSID, SMSTID, SMS_BEARERDATA(NAM DATA)] at block  78 . The serving MSC  18  then sends a SPACH notification of R-DATA to the MS  12  identifying the MS with PERMANENT_MSD at block  80 . Upon successful receipt, the MS  12  sends a SPACH confirmation at block  82  to MSC  18 . The SPACH is a logical channel used to send information to specific mobile stations regarding SMS point-to-point (“SMSCH”) paging and to provide an Access Response Channel (“ARCH”). The SPACH may be considered to be further subdivided into 3 logical channels, the SMSCH, ARCH and PCH, which are known in the art. The attributes of the SPACH are: unidirectional (downlink), shared, and unacknowledged. The SMSCH is point-to-multipoint. The ARCH and SMSCH are point-to-point. After SPACH confirmation, the MSC  18  sends programming R-DATA(NAM DATA) to MS  12  at block  84 . Methods of remote programming are disclosed, for example, in U.S. Pat. No. 5,301,223 entitled “Cellular Telephone System with Remote Programming, Voice Responsive Registration and Real Time Billing” to Amadon et al., and U.S. Pat. No. 5,297,192 entitled “Method and Apparatus for Remotely Programming a Mobile Data Telephone Set” to Gerszberg. The disclosures of these patents are hereby incorporated by reference. Upon successful receipt of the programming data, the MS  12  sends R-DATA_ACCEPT to the MSC  18  at block  86 . If no response is received, SMS data may be retransmitted. The MSC  18  in turn sends a successful download message SMDPP to the OTAF  26  at block  88 . The MS  12  writes NAM DATA to the NAM  37  or SIM  35  in programmable memory  32  at block  90 . 
     After the programming step has been completed, the WCS  10  may automatically initiate a call to the MS  12  to verify proper programming. This call may also be used to indicate to the user that the MS  12  is operational. When the user answers this call, a recorded message can be played indicating that the MS  12  is now operational. Alternatively, a predetermined signal on the phone such as a tone or a light may indicate that the MS  12  has been programmed. This signal may also be initiated by the page used to program the MS  12 . 
     As described above, a flag may be set in a programmable memory location  32  of the MS  12  to indicate that the MS  12  has been programmed for use in the WCS  10 . Accordingly, if the attempted programming is unsuccessful, the programming may be re-initiated, and the flag will indicate that the MS  12  has not yet been programmed. The flag may comprise a memory location in the programmable memory  32  in the MS  12 , which is programmed to a first variable when the MS  12  is manufactured to indicate that the MS  12  has not been programmed, and which is programmed to a second variable by the processor  30  of the MS  12  after the MS  12  has been successfully programmed. 
     The present invention has been shown and described in what are considered to be the most preferred and practical embodiments. It is anticipated, however, that departures may be made therefrom and that obvious modifications will be implemented by those skilled in the art.