Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
  • H04W4/12—Messaging; Mailboxes; Announcements
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L12/00—Data switching networks
  • H04L12/66—Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L12/00—Data switching networks
  • H04L12/54—Store-and-forward switching systems 
  • H04L12/56—Packet switching systems
  • H04L12/5601—Transfer mode dependent, e.g. ATM
  • H04L2012/5603—Access techniques
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
  • H04L69/08—Protocols for interworking; Protocol conversion
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W80/00—Wireless network protocols or protocol adaptations to wireless operation
  • H04W80/08—Upper layer protocols

Definitions

• the present invention relates to a compact packet-based data communication protocol particularly suitable for use with GSM-type mobile phones.
• IP Internet Protocol
• Packet based protocols divide transmission data into a number of packets, each transmitted over the network as a separate protocol data unit (PDU). Packets are routed over the network by routing nodes which maintain routing tables indicating the routes between themselves and other nodes and adapt the routes they forward traffic by according to network traffic and other factors. Each packet is numbered as it is transmitted so that the data can be re-ordered upon receipt and missing packets can be requested for re-transmission.
• PDU protocol data unit
• GSM Groupe Special Mobile
• a method of transmitting Protocol Data Units (PDU's) over a data communications network comprises the steps of: receiving a PDU for transmission; encoding the PDU into a number of alphanumeric data packets, such that each data packet is less than a predetermined size; associating an address frame with the or each data packet, the address frame including the destination of the or each data packet; and, transmitting the or each data packet.
• PDU's Protocol Data Units
• a particular advantage of the present invention is that Internet access can be provided to mobile telephones without adapting the GSM protocol or infrastructure the phone is currently running on.
• the step of encoding the PDU may comprise the step of applying an alphanumeric encoding scheme if the PDU is not wholly alphanumeric.
• the alphanumeric encoding scheme is preferably uuencoding.
• Uuencoding enables data to be sent over existing text-based links which have reserved characters without modification.
• the step of encoding the PDU may comprise the steps of: determining the length of the PDU; generating a data packet from the PDU, wherein if the PDU is greater than a predetermined size, it is divided up into a sequence of data packets.
• the step of generating a data packet may further comprise the step of associating a packet identifier with the generated data packet, wherein if a
• the packet identifier for each data packet identifies it as part of a divided PDU and identifies the relative position of the data packet in the sequence.
• the address frame may include a Short Message Service (SMS) address and the or each data packet is transmitted by SMS.
• SMS Short Message Service
• SMS Short Message Service
• GSM Global System for Mobile communications
• the reserved characters such as control characters
• the address frame may include a Cell
• Broadcast address and the or each data packet is transmitted by Cell Broadcast.
• the step of encoding the PDU into a number of alphanumeric data packets may include the step of compressing the PDU.
• a method of receiving Protocol Data Units (PDU's) transmitted over a data communications network may comprise the steps of receiving a number of alphanumeric data packets, removing the address frame associated with each data packet and regenerating a PDU from the number of received alphanumeric data packets.
• the step of regenerating a PDU may include uudecoding the number of received alphanumeric data packets.
• the step of regenerating a PDU may include the steps of ordering the received alphanumeric data packets in dependence on a packet identifier associated with each data packet, removing the packet identifier associated with each data packet and rejoining the data packets.
• the step of ordering the received alphanumeric data packets may include the step of detecting non- received data packets and requesting their retransmission.
• a system for transmitting Protocol Data Units (PDU's) over a data communications network comprises a receiver for receiving a PDU for transmission, an encoder for encoding the PDU into a number of alphanumeric data packets, such that each data packet is less than a predetermined size, an addressing system for associating an address frame with the or each data packet, the address frame including the destination of the or each data packet and a transmitter for transmitting the or each data packet.
• PDU's Protocol Data Units
• the encoder may apply an alphanumeric encoding scheme if the PDU is not wholly alphanumeric.
• the transmitter preferably comprises a Short Message Service (SMS) system for addressing and transmitting the or each data packet.
• SMS Short Message Service
• the system may further include a receiver for receiving Protocol Data Units (PDU's) transmitted over a data communications network by the transmission elements of the above system, the receiver including a receiver system for receiving a number of alphanumeric data packets, a processor for removing the address frame associated with each data packet and for regenerating a PDU from the number of received alphanumeric data packets.
• the processor may be configured to uudecode the number of received alphanumeric data packets.
• the processor may be configured to order the received alphanumeric data packets in dependence on a packet identifier associated with each data packet, to remove the packet identifier associated with each data packet and to rejoin the data packets.
• the processor is configured to detect non-received data packets and to request their retransmission.
• the receiver is preferably an SMS receiver, such as a GSM mobile telephone, and the alphanumeric data packets are received by SMS.
• the receiver may be a Cell Broadcast receiver and the alphanumeric data packets are received by Cell Broadcast.
• the transmitter may also be a GSM mobile telephone.
• the PDU's may comprise data resulting from browsing of, and/or interaction with, the World Wide Web, wherein the system may further comprise a World Wide Web server for acting as a gateway for PDU's for transmission to, and for reception from, the World Wide Web.
• the PDU's comprise data resulting from browsing of, and/or interaction with, the World Wide Web, wherein the SMS system is hosted by a World Wide Web server which also acts as a gateway for PDU's for transmission to and for reception from the
• alphanumeric characters comprise the following set:
• Figure 1 is a schematic diagram of a data communications network for use in the present invention
• Figures 2a and 2b are representations of data packet formats transmitted and received in a data communications session according to the present invention.
• Figures 3a-3e and 4a-4e are examples of data packets transmitted and received in a data communications session according to the formats defined with reference to Figure 2.
• Figure 1 is a schematic diagram of a data communications network for use in or with the present invention.
• a GSM service provider has a mobile telephone network comprising a number of transmission cells 10. The network is linked to an SMS system 20 which is in turn linked to a World Wide Web (WWW) server 30 which is connected to the WWW 40.
• WWW World Wide Web
• a user of a mobile telephone 50 in the transmission area of one of the cells 10 browses the WWW using a micro-browser installed on his mobile telephone 50. Due to the user's interaction with the micro-browser, requests for data from the WWW are issued by the micro-browser.
• the requests are encoded and transmitted by the mobile telephone as SMS messages addressed to the WWW server 30.
• the messages are treated as a normal SMS message and are forwarded by the cells 10 to the SMS system 20.
• the SMS system 20 passes the messages on to the WWW server 30.
• the WWW server 30 Upon receiving an SMS message, the WWW server 30 decodes it into an appropriate HTTP (HyperText Transport Protocol) request which it then processes.
• HTTP HyperText Transport Protocol
• Data received by the WWW server 30 via the WWW 40 in response to the HTTP request is encoded as an SMS message addressed to the micro- browser of the mobile telephone 50.
• the WWW server 30 passes the message to the SMS system 20 which transmits it to the mobile telephone 50 via the cells 10.
• the mobile telephone receives the message, decodes it and passes it to the micro-browser for the appropriate action such as displaying a WWW page to the user.
• Figures 2a and b are representations of the formats of data packets generated in accordance with the present invention.
• the transport protocol used by the mobile telephone 50 and WWW server 30 to generate SMS messages due to requests and decode received messages is divided into two layers: a session layer responsible for encoding and decoding data and requests into SMS format messages, and a transport layer responsible for preparing and addressing the SMS messages and error checking received messages. Due to the size limit for SMS messages, a request or a response that exceeds this limit must be divided into a number of discrete packets.
• the transport layer divides such messages into a number of packets, each transmitted as a separate SMS message. Received packetised messages are reassembled by the transport layer.
• SMS allows messages of 160 7-bit characters which must be uuencoded or 140 8-bit characters which do not need to be uuencoded.
• the remainder of the description relates to 160 7-bit character messages but the skilled reader will understand that the present invention is applicable to either type.
• Figure 2a is a representation of a message prepared by a session layer.
• a CommandlD field 100 indicating the type of command the message relates to (open, close, request, send or rerequest)
• header field The contents of the header field relate to optional data.
• Each header field includes a value followed by a NULL terminated string.
• a header may be formed of the following:
• the content type field may include, for example, one of the following type identifiers:
• An encoding field may specify a value corresponding to an encoding or compression scheme such as Huffman encoding or run length encoding.
• the agent profile is used to adapt the data type and/or content transmitted by a service or server depending on the type of device accessing the data. Due to the diversity of supported features by different browsers
• a profile identifies the main features of the browser such as support of HTML/HDML/WML, image types it can display, screen size, etc.
• the service or server can then adapt the data returned to the browser using this information.
• Figure 2b is a representation of a message prepared by the transport layer.
• a session layer message is processed and, if necessary divided into a number of packets having a maximum length of 157 bytes, shown as data field 200.
• a header is attached including a MessagelD field 210, packet number field 220, error check field 230 and packet total field 240.
• the messagelD 210 identifies the message the packet is associated with.
• each packet's header contains the same messagelD so that, upon receipt, the packets can be identified and merged together to reform the message.
• the packet number and packet total fields (220, 240) are also used in this respect as packets may be received in any order and packets may be missing. The number and total fields allow the receiver to re-order the packets and request re-transmission of missing packets.
• the error check field 230 indicates the type of error checking used on the accompanying data.
• Figures 3a-3e are representations of data packets transmitted and received in a data communication session using a protocol according to the present invention.
• Figure 3a is a representation of a data packet prepared by a session layer in response to a request by a mobile telephone's micro-browser for the URI (Universal Resource Indicator) "http://hdmlhost/home.hdml”.
• the message of Figure 3a is therefore passed to the transport layer.
• the transport layer Upon receipt, the transport layer determines that only 1 SMS message is required and therefore allocates the messagelD 1 , packet number 0, error check level 0 (no error checking) and packet total 0. This information is concatenated to the session message to produce the SMS packet of Figure 3b, which is then transmitted. Having received and decoded the SMS message, a server requests the
• the session level of the server takes the data and allocates a commandlD 4 (send), and a message size 207 (headers 6 + data 200 + terminator 1 ) which is encoded into 79+1 * 2 7 .
• a header field of content type 1 (HDML) is added, followed by the data (200 bytes) and the next commandlD 0 (no more messages).
• the assembled message as shown in Figure 3c is passed to the server's transport layer.
• the transport layer builds the first SMS packet having a MsglD of 1 , packet number 0, error check 0 and packet total 1.
• the resultant SMS message as shown in Figure 3d cannot hold all of the session layer's message and therefore only contains the first 151 bytes with the 9 bytes of headers.
• a second SMS packet having the same transport layer data as the first with the exception of packet number being 1 is generated to take the last 49 bytes of data, as is shown in Figure 3e. Both SMS packets are transmitted to the mobile telephone and are decoded, reconstituting the data for display by the micro-browser.
• Figures 4a-4d are representations of data packets transmitted and received in a data communication session using a protocol according to the present invention.
• Figure 4a is a representation of a data packet prepared by a session layer in response to a request by a mobile telephone's micro-browser for the URI (Universal Resource Indicator) "http://hdmlhost/home.hdml”.
• the message of Figure 4a is therefore passed to the transport layer.
• the transport layer Upon receipt, the transport layer determines that only 1 SMS message is required and therefore allocates the messagelD 1 , packet number 0, error check level 0 (no error checking) and packet total 0. This information is concatenated to the session message to produce the SMS packet of Figure 4b, which is then transmitted.
• a server Having received and decoded the SMS message, a server requests the URI via HTTP and receives 200 bytes of data in response.
• the 200 bytes are compressed by the server to 87 bytes.
• the session level of the server takes the compressed data and allocates a commandlD 4 (send), and a message size 96 (headers 8 + data 87 + terminator 1) which is encoded into 96+0 * 2 7 .
• Header fields of content type 1 , 2 (HDMLc) and Huffman encoding (6, 1 , 0) are added, followed by the data (87 bytes) and the next commandlD 0 (no more messages).
• the assembled message as shown in Figure 4c is passed to the server's transport layer.
• the transport layer builds the first SMS packet having a MsglD of 1 , packet number 0, error check 0 and packet total 0.
• the SMS packet is transmitted to the mobile telephone, decoded and then decompresed, reconstituting the data for display by the micro-browser.
• a uuencoding scheme is applied to received data packets in order to avoid attempts to transmit non-alphanumeric characters which SMS does not support.
• the present invention is applicable to many transmission protocols and mechanisms, for example Cell Broadcast.
• Cell Broadcasts and SMS alerts no initial request is made from the phone for data.
• a URI is created at a WWW server and transmitted to the phone according to some criteria such as a previous request to receive certain data or a decision by a service provider to notify some/all users of an event.
• the transport layer modifies message length accordingly.
• a Cell Broadcast message utilises the alert field, described previously, to identify the type of data transmitted and whether/how the user should be notified when the broadcast arrives.
• cell broadcast is only a one-way transmission mechanism from the server to any recipients in the respective cell, the protocol of the present invention could be used, for example, to broadcast pages with local information (e.g. where a local branch of a well-known store is).

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• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Mobile Radio Communication Systems (AREA)
• Data Exchanges In Wide-Area Networks (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 1999
  • 1999-12-01 GB GBGB9928354.1A patent/GB9928354D0/en not_active Ceased
• 2000
  • 2000-11-15 CN CN00805503A patent/CN1352844A/zh active Pending
  • 2000-11-15 EP EP00974555A patent/EP1180291A2/de not_active Ceased
  • 2000-11-15 JP JP2001541204A patent/JP2003516039A/ja not_active Withdrawn
  • 2000-11-15 WO PCT/EP2000/011431 patent/WO2001041391A2/en not_active Ceased
  • 2000-11-15 KR KR1020017009660A patent/KR20010101900A/ko not_active Withdrawn

Non-Patent Citations (1)

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