Patent Publication Number: US-2022222651-A1

Title: Proximity-based payments

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation under 35 U.S.C. § 120 of U.S. application Ser. No. 16/828,817, filed Mar. 24, 2020, which is a continuation under 35 U.S.C. § 120 of U.S. application Ser. No. 14/296,385, filed Jun. 4, 2014, now U.S. Pat. No. 10,614,445 entitled “PROXIMITY-BASED PAYMENTS,” which is incorporated by reference in its entirety herein. 
    
    
     BACKGROUND 
     Financial transactions are a crucial part of our everyday lives. On one end, there are financial transactions between merchants and customers. On the other end, there are financial transactions between customers. When two or more customers want to share the cost of a purchase, apportioning the cost between them can be difficult, especially when one or more of them want to pay by credit card. Consider, for example, the situation in which a social group gathers for a meal at a restaurant, where everyone is to pay for his or her own food and drink. When it comes the time to pay the check, the need of conducting payment from one party to another can create an inconvenient and sometimes awkward interruption in the social interaction of the group. When there is not enough cash in the social group to settle the bill, many customers also find annoying the need to remember and track down how much each party owes to another. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       One or more embodiments of the present invention are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements. 
         FIG. 1  illustrates an environment within which the proximity-based payment techniques introduced here can be implemented. 
         FIG. 2  illustrates an example of a mobile device implementing one or more techniques disclosed herein. 
         FIG. 3  illustrates an example of proximity-based payments being conducted by a customer&#39;s mobile device with other customers&#39; mobile devices. 
         FIG. 4  is a flow diagram illustrating an example of a process for conducting proximity-based payments between mobile devices. 
         FIGS. 5-6  are two flow diagrams illustrating optional features which can be implemented with the example process of  FIG. 4 , in accordance with some examples. 
         FIG. 7  is a flow diagram illustrating an example of an additional or alternative process for conducting proximity-based payments between mobile devices. 
         FIGS. 8A-8G  illustrate examples of various screen displays that can be generated by a mobile payment application on a customer&#39;s mobile device to enable proximity-based payment. 
         FIG. 9  is a high-level block diagram showing an example of processing system in which at least some operations related to the generation of the disclosed quick legend receipt(s) can be implemented. 
     
    
    
     DETAILED DESCRIPTION 
     References in this description to “an embodiment,” “one embodiment,” or the like, mean that the particular feature, function, structure or characteristic being described is included in at least one embodiment of the present invention. Occurrences of such phrases in this specification do not necessarily all refer to the same embodiment. On the other hand, the embodiments referred to also are not necessarily mutually exclusive. 
     It is observed that the aforementioned need of conducting payment from one party to another often arises in social gatherings and can create annoyance. There are traditional ways of handling this kind of situation. For example, in one common approach, one member of the group uses a credit card, and the other members of the group reimburse that person with cash for their portions. With this approach, it is inconvenient and often time-consuming to have to calculate how much each person (or each couple or family) owes and then collect cash from the other members of the group. Additionally, it is common that some members of the group end up paying more or less than their fair share. In another common approach, the group asks the waiter to split the check in a certain manner, and everyone then either pays cash or uses his or her own credit card. This approach can also be troublesome if the check is not being split equally, and regardless, it is inconvenient and time-consuming for the waiter. In any of these situations, the need to deal with these issues detracts from the social atmosphere of the event. 
     To service non-sophisticated consumers, payment from one party to another should remain simple and easy to execute. Introduced here are techniques that facilitate customers&#39; mobile devices to conduct proximity-based payments, which can further reduce the friction of conducting payments from one party to another. In the social dinning example discussed above, the techniques introduced here enable a customer (or a consumer, as used interchangeably herein) to pay another customer easily by using the customer&#39;s mobile device (e.g., a smartphone or tablet computer). 
     In short, the techniques involve communication among a mobile payment application installed on the customer&#39;s mobile device and a remote payment service system (PSS) (more of which is discussed below). The mobile payment application running on the customer&#39;s mobile device detects physical proximity of other customers&#39; mobile devices, and enables the user to specify to whom and how much payment should be made. The mobile payment application communicates this information to the PSS, which then executes or triggers execution of the transfer of funds to carry out the specified payment. In some embodiments, the communication to the PSS enables the PSS to look up additional contact information; then, in certain examples, the PSS can transmit the additional contact information to the mobile payment application so that the payment transfers can be more easily facilitated (e.g., by automatically entering, for the user, those additional information of those customers who are physically nearby the user). 
     As described further below, mobile devices implementing the techniques disclosed herein can detect another device (or devices) that is close by and conduct payments. In certain embodiments, the techniques introduced here can utilize wireless personal area network (WPAN) circuitry (e.g., Bluetooth, Bluetooth Low Energy (BLE), Infrared Data Association (IrDA), etc.) that is equipped on a mobile device to determine whether there is another mobile device that is within the network and, in some examples, how close the another mobile device is. Preferably using his or her mobile devices, a customer user who wishes to enjoy the proximity-based payment functionality sets up the functionality by entering information about the customer&#39;s financial account (e.g., debit card information). For example, the customer enters the financial information in the customer&#39;s mobile device, and the customer&#39;s mobile device uploads to the PSS the financial account information together with an identifier that uniquely identifies the mobile device (such as an International Mobile Station Equipment Identity (IMEI) code or a BLE identifier (BLE ID)) so that the customer&#39;s mobile device is associated with the financial account. 
     When there is another mobile device detected in the network, the mobile device verifies whether the detected mobile device wishes to participate in proximity-based payments (i.e., allowing other mobile devices to conduct proximity-based payments with it). If the mobile device finds that the detected device also has proximity-based payment functionality enabled, then the mobile device prompts the customer to select the detected device for conducting a payment. For example, the mobile device can display icons or names that are representative of all the detected devices nearby that have their proximity-based payment functionalities enabled. As is described in fuller detail below, the devices nearby can have ways to control whether to be detected by the mobile device, and if so, in what manner they are to be displayed. The payment either can be sending from the customer&#39;s mobile device to the detected device, or can be receiving from the detected device to the customer&#39;s mobile device. 
     Upon the customer&#39;s selection of the detected device, the customer&#39;s mobile device can ask the customer to enter or to confirm an amount for the payment. Then, if the payment is from the customer&#39;s device to the detected device, the customer&#39;s device can cause the amount of payment to be transferred from the financial account associated with the customer&#39;s device to the financial account associated with the detected device. In variations, this process can also be initiated when the customer&#39;s device receives a request (or invitation) for payment from the detected device. On the other hand, if the payment is from the detected device to the customer&#39;s device, the customer&#39;s device can send out a request or invitation for payment to the detected device. 
     The techniques introduced here enable one customer to pay another quickly and easily compared to traditional methods. Furthermore, without the prerequisites of a customer having any information (e.g., an email address or a phone number) about another, the introduced techniques enable users to conduct payments with each other as long as they are in physical proximity, thereby greatly reducing the potential for awkward interruptions to the social flow of group events due to bill splitting issues, even in group events that include multiple distinct social circles. The introduced techniques are also advantageous over several traditional means of providing direct payment between two parties, such as an Automated Clearing House (ACH) network. In particular, the ACH is an electronic network for financial transactions in the United States and enables credit transfers including direct deposit, but the ACH would require a trial deposit of a trivial amount (e.g., $1) to verify the financial account, the process of which may take days. Indeed, traditional ways of direct monetary transfer from one bank account to another often involve time-consuming verification processes, which may reduce or even defeat the convenience that the techniques introduced here aim to bring. 
     In the following description, the example of a social dinning event is used, for illustrative purposes only, to explain various aspects of the techniques. Note, however, that the techniques introduced here are not limited in applicability to dinning in restaurants or to any other particular kind of scenario. Additionally, although the following description adopts debit cards as an example for the financial account information, the techniques introduced here are not limited to use with debit cards or other types of payment cards; rather, the techniques can be employed with essentially any suitable financial account that traditionally would be involved in monetary transfers. Additionally, the term “sale,” as in point-of-sale (POS), refers to any type of payment-oriented transaction, including providing of a service, a lease or rental for example, and is not limited to an actual purchase. Note also that in this description, the term “user” generally refers to a consumer or a customer (as opposed to a merchant), except where otherwise indicated, and except that the term “user interface” does not necessarily refer to an interface used by a customer, as will be apparent from the context. 
     Additionally, while the customer generally uses a mobile device to conduct proximity-based payments in the embodiments emphasized herein, in other embodiments the consumer may use a processing device other than a mobile device to specify that information, such as a conventional personal computer (PC). In such embodiments, the mobile payment application can be replaced by a more conventional software application in such processing device, where such software application has functionality similar to that of the mobile payment application as described herein. 
       FIG. 1  illustrates an environment within which the proximity-based payment techniques introduced here can be implemented. The environment includes a mobile device  102  of a user  101  (also referred to as “customer” or “consumer”). Optionally, the environment can further include a merchant POS system of a merchant  100 . The mobile device  102  can be, for example, a smart phone, tablet computer, notebook computer, or any other form of mobile processing device. In some implementations, a mobile payment application  120  can run on the user&#39;s mobile device  102  to interact with other components in the environment; for example, in one embodiment, the mobile payment application  120  can receive a digital version of a transaction receipt from the merchant. The environment also includes a computer system  114  of the merchant&#39;s acquirer, a computer system  118  of an issuing bank, a computer system  116  of a card payment network, and a computer system  108  of a payment service (hereinafter “payment service system (PSS)  108 ”). Each of the aforementioned computer systems can include one or more distinct physical computers and/or other processing devices which, in the case of multiple devices, can be connected to each other through one or more wired and/or wireless networks. All of the aforementioned devices are coupled to each other through an internetwork  106 , which can be or include the Internet and one or more wireless networks (e.g., a wireless local area network (WLAN) and/or a cellular telecommunications network). 
     In a traditional credit card transaction, the merchant swipes the user&#39;s credit card through a card reader at the merchant&#39;s POS system  104 . The POS system  104  sends data read from the card (e.g., the cardholders name, credit card number, expiration date and card verification value (CVV)) to the computer system  114  of the merchant&#39;s acquirer (hereinafter “acquirer  114 ”). The acquirer  114  sends this data to the computer system  116  of the card payment network (e.g., Visa or MasterCard) (hereinafter “card payment network  116 ”), which forwards the data to the computer system  118  of the issuing bank (hereinafter “issuer  118 ”). If the transaction is approved by the issuer  118 , a payment authorization message is sent from the issuer  118  to the merchant POS system  104  via a path opposite of that described above. 
       FIG. 2  illustrates an embodiment of the user&#39;s mobile device  102  implementing one or more techniques disclosed herein. Note that the components shown in  FIG. 2  are merely illustrative; certain components that are well known are not shown for simplicity. Referring to  FIG. 2 , the mobile device  102  includes a processor  201 , a memory  203  and a display  202 . The mobile device  102  also includes a wireless personal area network (WPAN) circuit  204 , and optionally, a card reader  205 . The processor  201  can have generic characteristics similar to general purpose processors or may be application specific integrated circuitry that provides arithmetic and control functions to the mobile device  102 . The processor  201  can include a dedicated cache memory (not shown for simplicity). The processor  201  is coupled to all modules  202 - 205  of the mobile device  102 , either directly or indirectly, for data communication. 
     The memory  203  may include any suitable type of storage device including, for example, an SRAM, a DRAM, an EEPROM, a flash memory, latches, and/or registers. In addition to storing instructions which can be executed by the processor  201 , the memory  203  can also store data generated from the processor module  201 . Note that the memory  203  is merely an abstract representation of a generic storage environment. According to some embodiments, the memory  206  may be comprised of one or more actual memory chips or modules. The display  202  can be, for example, a touchscreen display, or a traditional non-touch display (in which case the mobile device  102  likely also includes a separate keyboard or other input devices). Optionally, the mobile device  102  can include or be coupled to a card reader  205 , which can be any suitable physical card reader that can read a physical card, such as a magnetic stripe card reader, an optical scanner, a smartcard reader, a radio frequency identification (RFID) reader, or the like. 
     The WPAN circuitry  204  is wireless communication circuitry that can form and/or communicate with a computer network for data transmission among electronic devices such as computers, telephones, and personal digital assistants. WPANs can be used for communication among the personal devices themselves or for connecting to a higher level network (e.g., a WLAN) and the Internet. Some examples of the WPAN circuitry  204  include IrDA, Bluetooth (including aforementioned BLE), Z-Wave, ZigBee, Body Area Network, and so forth. In some embodiments, the WPAN circuitry  204 &#39;s connection can be bootstrapped by a near field communication (NFC) connection. 
     A mobile payment application  220  may be or include a software application, as henceforth assumed herein to facilitate description. As such, the mobile payment application  220  is shown as being located within the memory  203 . Alternatively, the mobile payment application  220  could be a hardware or a firmware component (which may include a mobile payment software application). 
     In accordance with some embodiments of the techniques introduced here, the mobile payment application  220  includes a proximity-based payment module  222  that implements the techniques introduced here and provides proximity-based payment functionalities to the mobile device  102 . The proximity-based payment (PBP) module  222  communicates with the mobile payment application  220 . The PBP module  222  may also communicate with the display  202 , either directly or through the mobile payment application  220 . Similar to the mobile payment application  220 , the PBP module  222  can be software, hardware, or a combination thereof. As illustrated in  FIG. 2 , the PBP module  222  can be an integral part of the mobile payment application  220 . Alternatively, although not shown in  FIG. 2  for simplicity, the PBP module  222  can be logically separate from the mobile payment application  220  but operate “alongside” it (such as the case of having two separate mobile software applications installed on the mobile device  102 ). Further details on how various embodiments of the proximity-based payment module  222  operate in implementing the proximity-based payment techniques disclosed here are discussed below. 
     In some embodiments, the mobile application  220  can employ a number of techniques for simplifying customer-to-customer transactions by use of an email mechanism. Some examples of these techniques are discussed in U.S. patent application Ser. No. 14/246,017, entitled “PAYMENT TRANSFER BY SENDING EMAIL,” filed Apr. 4, 2014, which is assigned to the same assignee as the present application. In general, these techniques enable a simplified payment transaction system for ordinary consumers without the hassle of having to sign up, to remember a user account associated with a password, and to login for sending or receiving every payment transaction, while not sacrificing the essential security feature of authenticating the user for every payment transaction. To send a payment, the user needs to only specify a receiver email address in an email. When the payment email is created, the email can be auto-populated with a security token. The email can also carbon copy (Cc), blind carbon copy (Bcc), or add as a recipient (To) a payment processing email address. When the email is sent, the payment processing system  108  can receive the payment email (e.g., by receiving the payment email through the payment processing email address) and generate a payment receipt interface for the receiver of the email. 
     Although these embodiments of the mobile application  220  can provide easy execution of customer-to-customer financial transactions (e.g., payment transfers), it is observed here that the above-described process can be even further simplified if the requirement for identifying the email addresses of the receivers (or payers, whichever the situation may be) can be removed. Accordingly, by one or more techniques discussed here, the proximity-based payment module  222  provides the mobile payment application  220  the ability to identify another customer that is nearby, and the ability to automatically enter contact information (e.g., email) of the identified, nearby customer for payment transaction, such that interruption caused by payment transfers to the flow of a social event (e.g., asking another customer for his or her email address) can be further reduced. More implementation details of the proximity-based payment module  222  is discussed blow. 
       FIG. 3  illustrates an example of proximity-based payments being conducted by a customer&#39;s mobile device  102  with other customers&#39; mobile devices  112  and  122 .  FIGS. 4-7  are flow diagrams illustrating various examples of a process (e.g., to be executed by the mobile payment application  120 ) for conducting proximity-based payments among mobile devices  102 ,  112 , and  122 .  FIGS. 8A-8G  illustrate examples of various screen displays that can be generated by a mobile payment application on a customer&#39;s mobile device to enable proximity-based payment. For purposes of illustration, the process of  FIGS. 4-7  is explained with reference to certain elements illustrated in  FIG. 3 . 
     As illustrated in  FIG. 3  and continuing with the above social dinning example, users  111  and  121  are in proximity with the user  101  after the dinning and would like to settle the bill. For example, the user  101  needs to make payment to user  111  and also needs to receive payment from user  121 . 
     In preferred embodiments, before the user  101  can pay the user  111 , the user  101  enables the proximity-based payment functionality in the mobile payment application  120  by entering information about a financial account of the user  101 . For example, the user  101  enters information about his or her debit card  103  (e.g., through the card reader  205  or other input devices present on the mobile device  102 ) into the mobile payment application  120 . After the mobile payment application  120  receives ( 510 ) the information about the financial account, the application  120  transmits ( 520 ) the information entered by the user  101  together with an identifier that uniquely identifies the mobile device  102  to a remote server (e.g., the PSS  108 ) so that the mobile device  102  is associated with the user  101 &#39;s financial account (as indicated by the card  103 ). For example, the identifier can be the IMEI code of the mobile device  102 . In one embodiment, the identifier is a BLE ID, a unique ID identifying each and every BLE chip. The transmission from the application  120  to the PSS  108  can be encrypted. 
     Note that, although a debit card is used for purposes of explaining the present techniques, the card  103  is not limited to an actual card of such kind; in alternative examples, the card  103  can represent an online bank account or any suitable payment account that can be used by the user  101  to transfer and/or receive currency. Further, in some embodiments, one mobile device can be associated with more than one financial accounts; in these embodiments, the mobile payment application  120  can adapt well-known multi-account managing techniques that allow the user  101  to identify which financial account should be used for conducting proximity-based payments. As an alternative, the user  101  can enter his or her financial account information along with the identifier that uniquely identifies the device  102  directly onto the PSS  108  (e.g., via a webpage that the PSS  108  hosts). In this alternative case, the PSS  108  can separately verify the correctness of the received information (e.g., by sending a text message to the mobile device  102 ). In other embodiments, the user  101  can associate the mobile device  102  and/or his particular instance of the mobile application  120  by registering (e.g., his email address) with the PSS  108 . 
     Additionally or alternatively, the user  101  can enter other contact or identification information into the mobile payment application  120 . Similar to the aforementioned financial account information, these contact or suitable identification information of the user  101  can be communicated to the PSS  108  so that these information can be associated to the mobile device  102 . For example, in certain implementations where the mobile payment application  120  can initiate or cause proximity-based payment transaction by use of emails, the user  101  should enter his or her email address so that the PSS  108  can have the email address as one of the mechanisms available for identifying the mobile device  102 . Note that, in some these examples that can cause payment transfers using email, the financial account information (e.g., the debit card information) need not be entered into the PSS  108 —the email address can be used for payment transfers instead. 
     Similar to how the user  101  enables the proximity-based payment functionality by associating the mobile device  102  with the debit card  103 , the users  111  and  121  each enable the proximity-based payment functionality on their mobile payment applications  120  by respectively associating the mobile device  112  with the debit card  113 , and the mobile device  122  with the debit card  123 . For certain implementations where the mobile payment application  120  can initiate proximity-based payment transaction by utilizing emails, the users  111  and  121  each should enter their email addresses into their respective mobile payment applications  120 . 
     During normal operation, the mobile device  102  can conduct proximity-based payments with the mobile device  112  by first detecting ( 410 ) that the mobile device  112  is within the wireless network, such as within range of a BLE network. The detection can be initiated, in one example, when the user  101  selects to activate the mobile application  120  on the device  102 , or in another example, when the user  101  selects to switch the mobile application  120  to run in foreground. More specifically, the mobile device  112  can sense the BLE devices (e.g., the device  112 ) that are nearby using BLE proximity sensing, e.g., estimating physical proximity using the radio receiver&#39;s received signal strength indication (RSSI) value. In other examples, the mobile application  120  may invoke other types of short-range wireless communication feature of the mobile device  102 , such as infrared communication, WiFi, or the like. 
     To balance security, privacy, and convenience, a mobile device can choose (e.g., by turning off a particular WPAN circuit, by closing the mobile software application  120 , or by refusing to be connected for proximity-based payment) whether it can be detected by other mobile devices within the network. 
     Depending on the implementation, some embodiments of the mobile payment application  120  only allows a mobile device to be discoverable when an instance of the mobile payment application  120  is running; for example, some embodiments of the application  120  allow proximity-based payment only when they are operating in the foreground, and some other embodiments of the application  120  allow proximity-based payment regardless of whether they are operating in the foreground or the background. Additionally or alternatively, the mobile payment application  120  can require a password before another mobile device attempts to detect or connect for proximity-based payment purposes. The password that authenticates a first mobile device (e.g., device  102 ) to conduct proximity-based payments with a second mobile device (e.g., device  112 ) is designated by a user of the second mobile device. The password protection is preferred in some implementations of the mobile payment application  120  which can remain in the background and broadcast about its capability to conduct proximity-based payment. 
     In some embodiments, a user can select to accept or refuse to conduct proximity-based payment with some particular mobile devices but not others. In these embodiments, the mobile payment application  120  of the mobile device  102 , for example, can send out a query to the mobile payment application  120  of the mobile device  112 , and the mobile device  112  can send out a signal (e.g., in response to the query) indicating whether the mobile device  112  allows conducting payments with the mobile device  102 . In one example, the mobile device  102  also measures a received signal strength of a beacon signal sent from the mobile device  112 , and the mobile device  112  is only considered detected when the received signal strength of the beacon signal sent from the mobile device  112  exceeds a predetermined threshold, i.e., when the mobile device  112  is close enough. In variations, the user can approve a nearby mobile device for a one-time-only proximity-based payment. 
     In addition or as an alternative to aforementioned ways of directly detecting proximity of other devices, the mobile payment application  120  of the mobile device  102  can indirectly detect the physical proximity of the mobile devices (e.g., device  112 ). In one example, even though the two devices (e.g., device  102  and  112 ) may not be within the same wireless network (e.g., a BLE network), the two devices can individually and separately determine their locations and transmit their locations back to the PSS  108 , which can in turn determine that the two devices are in physical proximity for conducting proximity-based payments. How each device can determine its own physical location can be achieved through various means, for example, location calculation based on a global positioning satellite receiver, or triangulation from a number of nearby wireless base stations. 
     In this way, the mobile device  102  can identify, among the nearby devices within the wireless network, which devices are suitable candidates for conducting proximity-based payments by detecting, for example, which devices have their mobile payment application  120  up and running and with strong BLE signals. These features and options can also be adjusted depending on the user&#39;s preference in one or more embodiments. 
     Referring back to  FIG. 3 , after the mobile device  112  is detected by the mobile device  102 , the mobile device  102  verifies ( 420 ) with the PSS  108  that the mobile device  112  is eligible for proximity-based payment; that is to say, the mobile device  102  verifies ( 420 ) with the PSS  108  that the user  111  has completed the aforementioned card association process and that the mobile device  112  is indeed associated with the card  113 . Specifically, in at least those embodiments which employ BLE for conducting proximity-based payments, the mobile device  102  receives an identifier that uniquely identifies the mobile device  112  during the detection phase. As such, the mobile device  102  can verify with the PSS  108  by transmitting the identifier received from the mobile device  112  to the PSS  108  to ascertain the mobile device  112 &#39;s eligibility for conducting proximity-based payments. 
     Depending on the embodiment, either after the mobile device  112  is detected or after the mobile device  112  is verified, the mobile device  102  can receive user information about the mobile device  112  (e.g., the user  111 &#39;s name, nickname, portrait, email or contact information, etc.) from the PSS  108 . The mobile device  102  can display the received user information on the display of the mobile device  102  for the user  101  to identify the user  111 . In some examples, the mobile device  112  is displayed as an icon once detected, and the icon is replaced by the user information once the mobile device  112  is verified by and the user information received from the PSS  108 . In various embodiments, the user of the detected device has control over what user information is to be displayed. After the user information is received, a screen such as  FIG. 8A  can be displayed by the mobile application  120  to the user  101 . As shown in  FIG. 8A , the displayed screen can show a list that includes the users (e.g., user  802 ) of those detected devices that are detected in proximity for the user  101  to select (e.g., for purposes of conducting proximity-based payments). These users can be further identified by an icon  804  and a description  806  to indicate that they are displayed for the reasons of being in proximity. Other users, such as the users who has recently conducted payments with the user  101 , can also be displayed in the list.  FIG. 8B  shows an alternative implementation of the screen of  FIG. 8A . 
     In some embodiments, either the mobile application  120  or the PSS  108  can identify, from those physically-proximate devices, a list of devices with users that are socially connected to the user  101 . Then, the user  101  can configure the mobile application  120  so that it only provides information regarding identities of the users socially connected to the user  101 . More specifically, in some embodiments, the mobile application  120  can detect people in the vicinity (e.g., for those people that have their “detectability” turned on) The proximately-located devices can either be discovered directly by the mobile device  102  using, for example, BLE, or can be discovered by the PSS  108  based on the PSS  108 &#39;s understanding of devices located in proximate geographic regions. Either way, the PSS  108  or the mobile application  120  can recognize a list of people nearby, but only provides information relating to people known or otherwise socially connected with the user to be displayed as people in the proximate list. In some examples, a person can be regarded as “socially connected” because the user  101  has previously had a payment transfer or financial transaction with this person. In other examples, either the mobile application  120  or the PSS  108  can have access to the user  101 &#39;s social network account (e.g., a Facebook™, a LinkedIn™, or other suitable social networking sites) and determines that this person is socially connected to (e.g., within a social circle of) the user  101 . 
     Moreover, after aforesaid measurements of received signal strengths sent from all the detected mobile devices (e.g., devices  112  and  122 ) in proximity (e.g., within the BLE network), the mobile device  102  can sort all detected mobile devices based on their received signal strengths. As a variation, the mobile device  102  can also sort all detected mobile devices based on a frequency of past payments conducted between the mobile device  102  and each of the detected mobile devices. For example, the user  101  can set up, in the mobile device  102 , a black list for those devices that are disallowed for proximity-based payment, a white list for those that are allowed, and/or a favorite list for those that are to be displayed on the top of the list (or as highlighted in a map) of all detected devices. 
     By displaying information indicative of the mobile device  112  to the user  101 , the mobile device  102  prompts ( 430 ), via the display of the mobile device  102 , the user  101  to select or confirm the mobile device  112  for a proximity-based payment. As discussed above, the payment can be from or to the mobile device  102 , which can be chosen by the user  101 . As illustrated in the example scenario of  FIG. 3 , because the payment is assumed to be made from the mobile device  102  to the mobile device  112 , upon selection (e.g., by a click on the displayed screen of  FIG. 8A  or  FIG. 8B ) from the user  101  of the mobile device  112 , the mobile device  112  prompts ( 430 ) the user  101  to enter or approve an amount for the payment to the user  111  of the mobile device  112 , such as shown in an example display illustrated in  FIG. 8C . In an additional or alternative embodiment, an example interface illustrated in  FIG. 8D  can be used to replace the interfaces illustrated in  FIGS. 8A-8C . Note that the display of  FIG. 8D  includes an input area  808  (which is labeled as “To:” field) that can display the detected, nearby users. The interface of  FIG. 8D  also provides the amount input functionality of  FIG. 8C . Depending on the application, the example display of  FIG. 8D  may be more beneficial than that of  FIGS. 8A-8C  because it reduces the number of interfaces that the user  101  has to go through to conduct the payment transfer, thereby increasing the convenience factor. 
     Note that, as is further discussed below, in the examples where the mobile device  102 &#39;s proximity-based payment is initiated in response to a request from the mobile device  112 , it may not be necessary for the user  101  to enter the amount for the payment; because the amount can be received from the mobile device  112 , the user  101  may only need to approve (rather than enter) the amount for the payment. By the same token, it may not be necessary for the user  101  to select the mobile device  112 ; if the payment is initiated in response to the mobile device  112 &#39;s request, then the user  101  may only need to confirm (rather than select) the mobile device  112  for the payment. For example, in the display illustrated in  FIG. 8E , trusted contacts can be pre-filled in the To: field  810 . In some embodiments, trusted contacts are also indicated by a predetermined icon  812 . Optionally, a keyboard  814  can be displayed (e.g., upon the user  101  selecting the To: field  810 ) to enable search or edits. 
     After the payment information is confirmed by the user  101 , the mobile device  102  causes ( 440 ) the amount to be transferred from the financial account associated with the mobile device  102  to the financial account associated with the mobile device  112 . More specifically, after the user  101  has input or confirmed the payment information to the mobile device  102 , the mobile payment application  120  causes the mobile device  102  to transmit a message to convey that payment information to the PSS  108 . The PSS  108  then executes or triggers a money transfer process to carry out the payment, according to the payment information received from the mobile device  102 . In some examples, to cause the PSS  108  (for example) to carry out the payment, the mobile device  102  communicates with the PSS  108  the unique identifier of the payer (which in this case, mobile device  102 ), the unique identifier of the payee (which in this case, mobile device  112 ), and the amount to be transferred. The mobile application  120  can display a transmitting screen and a confirmation screen, such as respectively illustrated in  FIGS. 8F and 8G , to the user  101  so as to keep the user  101  informed of the status of the payment transfer. 
     In some implementations, the mobile application  120  can transmit cause to the PSS  108  to conduct payment transfers between the user  101 &#39;s financial account and another person&#39;s financial account that is identified by the user  101 . For example, the mobile application  120  can communicate with the PSS  108  by sending an email, a text message, a multimedia message, or a message that uses a proprietary communication protocol between the mobile application  120  and the PSS  108 . 
     In some examples, the email is generated by an email application separate from the money-transfer application (e.g., a native email application or a third-party email application, such as an Gmail™ application). The email can include an email address associated with the PSS  108 . The email can further include, for example, in its body or header portion, an indication of the monetary amount to be transferred to or from the user  101 &#39;s financial account. In some implementations, the email is generated with pre-populated information including (1) an email address associated with the PSS in an addressee filed and (2) the monetary amount, so that the user  101  only needs to select the send button (such as the “SEND” button shown in  FIG. 8C ). 
     Note that, in some embodiments, the email is generated but not displayed to the user  101 , and after the email is generated, the email is sent in the background using the email application without user intervention. In some of these embodiments, once the mobile application  120  has received the monetary amount and the identities of the selected users, the mobile application  120  can automatically cause (e.g., by generating an email or a message and sending the email to the PSS  108 ) the PSS  108  to perform the payment transfer in the background, without the user actually seeing the email or the message and without the need for the user to instruct an email application to send. In this way, since all the required information is already pre-populated, the mobile application  120  improves the user experience by simplifying the payment transfer process, which only requires the user to initiate the process by hitting the “send” button. The user need not see the background process of an email being generated by, for example, an email application of the mobile device  102 . 
     Note that the proximity-based payment from the mobile device  102  to the mobile device  112  can be initiated in response to the mobile device  102  receiving ( 610 ), from the mobile device  112 , a request for the payment to the user  111 . As mentioned above, the request can include the amount for the payment to the user  111  so that the user  101  does not need to specify the amount. 
     As mentioned above, in some implementations, the mobile payment application  120  can initiate customer-to-customer payment transfers by means of email. In these implementations, the mobile payment application  120  utilizes a third-party email application (e.g., a Gmail™ application) located on the mobile device  102  to transmit an email message that includes, for example, a payment amount to be transferred to a recipient, the recipient&#39;s name, a request for the PSS  108  to transfer the payment amount to the recipient, and a message token. 
     In one example, the user can enter an amount of payment on either the mobile payment application  120  or in the “SUBJECT” field of the third-party email application. The user can also include a message in the body of the email being drafted on the native email application. A security token can be embedded in the email being drafted and can include information regarding sender email address, device characteristic(s) and/or identifier of the payment sender device, financial account information of the sender user (e.g., debit card account information or credit card account information), or any combination thereof. It is noted that even without the financial account information of the sender user, the email can still be sent from the email application. For example, if no financial account information is embedded in the email, the PSS  108  can send a financial account request email to the sender email address requesting that financial account information be entered. The financial account request email can include a secure link to enter the financial account information, such as a debit card number or a credit card number and associated authentication information (e.g., expire date, ZIP Code, PIN number, or security code). After the user  101  chooses to send the email message, a copy of the message is also sent to the PSS  108 . The PSS  108  can analyze the email message, identify the mobile device  102 , verify that the email message has been sent from an email address of the user  101 , and verify that the mobile device  102  is the only one capable of having produced the email message. Having verified the email message (and the authenticity of the request to transfer money), the PSS  108  initiates the process to transfer the payment amount. However, as said above, the user  101  typically still needs to specify a recipient email address (e.g., such as that of the user  111 ) in the “TO:” field of the third-party email application. 
     By adapting the techniques introduced here in these implementations, the above process of initiating payment transfers via email can be further simplified. Before the email (i.e., the payment transaction email) is drafted, the mobile payment application  120  can detect the physical proximity of the mobile device  112 , communicate this information regarding its nearby mobile devices to the PSS  108 , and receive ( 425 ) relevant intelligence related to the nearby mobile devices (such as email address of the user  111 ) from the PSS  108 . Then, the mobile payment application  120  can automatically enter the received information for the user  101  for facilitating the proximity-based payment transfers. For example, the mobile payment application  120  can prompt the user  101  to select from a list of potential receivers (of the payment) that have been detected nearby, and the user  101  is given the choice to select or not select each potential payee. In variations, the mobile application  120  can generate a list of suggested payers based on, for example, the consumer&#39;s address book stored in the mobile device  120  and/or the consumer&#39;s recently used contacts stored on the mobile device  120 . Upon the user  101  indicating that he is satisfied with the selections (e.g., by clicking a “Pay” button provided on a user interface), the mobile payment application  120  can proceed with the next steps of the payment transfer procedures (e.g., launching the third-party email application of the mobile device  120  to draft a payment transaction email). 
     In accordance with some embodiments, the mobile device  102  can also actively send out request for payment using the proximity-based payment techniques. In the example of  FIG. 3 , when the user  101  desires to collect payment from the user  121 , the mobile device  102  first detects that the mobile device  122  is in proximity (e.g., within the BLE network) in ways described above. Similarly to how the mobile device  102  establishes proximity-based payment with the mobile device  112 , the mobile device  102  can also receive, from the mobile device  122 , a signal indicating whether the it allows conducting payments with the mobile device  102 . 
     After detecting and verifying the mobile device  122 &#39;s eligibility for conducting proximity-based payments, the mobile device  102  can enable ( 710 ) the user  101  to request a payment from the user  121  by prompting the user  101  to (a) select the mobile device  121  for the payment, and (b) specify an amount for the payment. Adapting the techniques herein, various embodiments of the mobile payment application  120  can let the user  101  enter how many shares of payments in total, and can let the user  101  choose how to split the bill (e.g., by spreading out evenly, by specifying an amount for each share, etc.). Thereafter, the mobile device  102  transmits ( 720 ) (e.g., via the BLE network), to the mobile device  122 , a request for the payment. 
     In the case that certain parties in the social dinning event are not eligible for proximity-based payment (e.g., because their mobile devices are not present, or their mobile payment application are shut off), the mobile payment application  120  can still enable the user  101  to request a payment by (a) prompting the user  101  to enter an electronic mail address of such party, and (b) transmitting, to the electronic mail (email) address, a request for the payment. Note that, after the mobile device  102  sends out the request to the mobile device  122 , the mobile device  122  can perform proximity-based payment to the mobile device  102  in a similar manner as how the mobile device  102  conducts proximity-based payment to the mobile device  112 . For those embodiments that utilize email as means for facilitating the payment transfer, the email addresses associated with those devices that are detected in proximity to the mobile device  102  can be transmitted from the PSS  108  to the mobile device  102 . Also, using similar techniques introduced here, the mobile payment application  120  can facilitate payment transfers with (including from and to) multiple other devices that are nearby. For example, depending on the implementation, the mobile payment application  120  can send out a single email to multiple recipients, or separate emails to each individual recipients. 
     In the aforementioned manner, the techniques introduced here enable one customer to pay another quickly and easily compared to traditional methods. Furthermore, without the prerequisites of a customer having any information (e.g., an email address or a phone number) about another, the introduced techniques enable users to conduct payments with each other as long as they are in physical proximity, thereby greatly reducing the potential for awkward interruptions to the social flow of group events due to bill splitting issues, even in group events that include multiple distinct social circles. 
       FIG. 9  is a high-level block diagram showing an example of a processing device  900  that can represent any of the devices described above, such as the mobile device  102 , the merchant POS system  104 , payment service system  108 , acquirer system  114 , card payment network  116 , or issuer system  118 . As noted above, any of these systems may include two or more processing devices such as represented in  FIG. 9 , which may be coupled to each other via a network or multiple networks. 
     In the illustrated embodiment, the processing system  900  includes one or more processors  910 , memory  911 , a communication device  912 , and one or more input/output (I/O) devices  913 , all coupled to each other through an interconnect  914 . The interconnect  914  may be or include one or more conductive traces, buses, point-to-point connections, controllers, adapters and/or other conventional connection devices. The processor(s)  910  may be or include, for example, one or more general-purpose programmable microprocessors, microcontrollers, application specific integrated circuits (ASICs), programmable gate arrays, or the like, or a combination of such devices. The processor(s)  910  control the overall operation of the processing device  900 . Memory  911  may be or include one or more physical storage devices, which may be in the form of random access memory (RAM), read-only memory (ROM) (which may be erasable and programmable), flash memory, miniature hard disk drive, or other suitable type of storage device, or a combination of such devices. Memory  911  may store data and instructions that configure the processor(s)  910  to execute operations in accordance with the techniques described above. The communication device  912  may be or include, for example, an Ethernet adapter, cable modem, Wi-Fi adapter, cellular transceiver, Bluetooth transceiver, or the like, or a combination thereof. Depending on the specific nature and purpose of the processing device  900 , the I/O devices  913  can include devices such as a display (which may be a touch screen display), audio speaker, keyboard, mouse or other pointing device, microphone, camera, etc. 
     Unless contrary to physical possibility, it is envisioned that (i) the methods/steps described above may be performed in any sequence and/or in any combination, and that (ii) the components of respective embodiments may be combined in any manner. 
     The techniques introduced above can be implemented by programmable circuitry programmed/configured by software and/or firmware, or entirely by special-purpose circuitry, or by a combination of such forms. Such special-purpose circuitry (if any) can be in the form of, for example, one or more application-specific integrated circuits (ASICs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), etc. 
     Software or firmware to implement the techniques introduced here may be stored on a machine-readable storage medium and may be executed by one or more general-purpose or special-purpose programmable microprocessors. A “machine-readable medium”, as the term is used herein, includes any mechanism that can store information in a form accessible by a machine (a machine may be, for example, a computer, network device, cellular phone, personal digital assistant (PDA), manufacturing tool, any device with one or more processors, etc.). For example, a machine-accessible medium can include recordable/non-recordable media (e.g., read-only memory (ROM), random access memory (RAM), magnetic disk storage media, optical storage media, flash memory devices, etc.). 
     Note that any and all of the embodiments described above can be combined with each other, except to the extent that it may be stated otherwise above or to the extent that any such embodiments might be mutually exclusive in function and/or structure. 
     Although the present disclosure has been described with reference to specific exemplary embodiments, it will be recognized that the techniques introduced here are not limited to the embodiments described. Accordingly, the specification and drawings are to be regarded in an illustrative sense rather than a restrictive sense.