Electronic mail system for rearranging stored mail data according to monitored data receiving condition

• US 6,735,618 B1
• Filed: 06/02/2000
• Issued: 05/11/2004
• Est. Priority Date: 06/04/1999
• Status: Expired due to Fees

• Current Assignee: Lenovo Innovations Ltd Hong Kong (Lenovo Group Ltd.)
• Original Assignee: NEC Corporation
• Inventors: Niwa, Yushi
• Primary Examiner(s): Wiley, David
• Assistant Examiner(s): Collins, Scott M.
• Application Number:
  US09/586,621
• Time in Patent Office: 1,439 Days
• Field of Search: 709/206, 709/207, 455/466, 455/412.1, 455/412.2, 455/115.3, 455/226.2, 455/226.4
• US Class Current: 709/207
• CPC Class Codes: H04L 51/226 Delivery according to priorities
• CPC Class Codes: H04L 51/58 Message adaptation for wireless communication
• CPC Class Codes: H04W 4/12 Messaging; Mailboxes; Announcements

Abstract

An electronic mail system for efficiently transmitting mail data according to a change of the transmission condition of the wireless transmission path is disclosed. The system comprises a mail sender including a mail receiving unit, storage device, mail sending unit, command interpreting section, and mail order rearranging section, and a mail receiver including a mail receiving unit, a receiving condition monitoring section, and a command issuing section. The mail receiving unit monitors the condition of receiving mail data at predetermined intervals, and generates a detection signal when the receiving condition changes. According to the detection signal, the mail receiver sends a command ordering the rearrangement of the mail data. The mail sender receives the command, and rearranges the mail data stored in the storage device.

Claims

1. An electronic mail system comprising:

a mail server having a mail sender which is connected to a first communication network including a data communication network and which receives an electronic mail and sends the received electronic mail to a relevant client;

a client having a mail receiver for receiving the electronic mail sent from the mail sender; and

a second communication network including a wireless transmission path, for connecting the mail server and the client, wherein;

the mail sender comprises;

a first mail receiving unit for receiving mail data of each electronic mail sent via the first communication network,

a storage device for storing the mail data received by the first mail receiving unit in turn;

a mail sending unit for reading out the mail data stored in the storage device, and sending the readout mail data to the second communication network;

a command interpreting section for receiving and interpreting a command, generated by the client, sent via the second communication network, and outputting a signal ordering rearranging the mail data stored in the storage device in response to receipt of said command; and

a mail order rearranging section for rearranging the order of the mail data stored in the storage device, based on the signal sent from the command interpreting section, and

the mail receiver comprises;

a second mail receiving unit for receiving a wireless signal corresponding to the readout mail data from the second communication network, and demodulating and storing the mail data from the received wireless signal, and monitoring the received wireless signal of the mail data so as to detect a change of a receiving condition of the received wireless signal and output a detection signal, said receiving condition corresponding to an intensity of the received wireless signal;

a receiving condition monitoring section for receiving the detection signal indicating a change of the receiving condition from the second mail receiving unit, and, in response thereto, outputting a signal ordering the issue of said command; and

a command issuing section for sending said command according to the output from the receiving condition monitoring section to the second communication network.

2. An electronic mail system as claimed in claim 1, wherein the second mail receiving unit comprises a radio wave monitoring section for detecting and outputting the intensity of the received radio wave of the wireless signal at predetermined intervals, and generates the detection signal indicating a change of the receiving condition based on the output from the radio wave monitoring section.

3. An electronic mail system as claimed in claim 2, wherein the output from the radio wave monitoring section is compared with a predetermined threshold value, and the detection signal is generated when the intensity of the received radio wave becomes lower than the threshold value.

4. An electronic mail system as claimed in claim 2, wherein a variation of the intensity of the received radio wave per unit time is calculated based on the output from the radio wave monitoring section, and the detection signal is generated when the variation becomes larger than a predetermined threshold value.

5. An electronic mail system as claimed in claim 1, wherein:

the mail data are sent to the mail receiving unit in a divided form; and

the second mail receiving unit comprises a mail receiving section for reconstructing and outputting the mail data corresponding to an electronic mail, and also outputting information on the size of the reconstructed mail data at predetermined intervals; and

the second mail receiving unit calculates the speed of reconstruction of the mail data at predetermined intervals based on the data size information output from the mail receiving section, and generates the detection signal indicating a change of the receiving condition based on the calculated speed of reconstruction.

6. An electronic mail system as claimed in claim 5, wherein the second mail receiving unit compares the speed of mail data reconstruction with a predetermined threshold value, and generates the detection signal when the speed becomes lower than a predetermined threshold value.

7. An electronic mail system as claimed in claim 5, wherein the second mail receiving unit calculates a variation of the speed of mail data reconstruction per unit time, and generates the detection signal when the variation becomes larger than a predetermined threshold value.

8. An electronic mail system as claimed in claim 1, wherein the second mail receiving unit comprises a storage device for storing the received mail data and outputting information on the vacant capacity at predetermined intervals, and generates the detection signal indicating a change of the receiving condition when the vacant capacity of the storage device, detected according to the information on the vacant capacity, becomes lower than a predetermined capacity.

9. An electronic mail system as claimed in claim 1, wherein:

the second mail receiving unit comprises an input device for a user of the mail receiver to input a signal for communicating a change of the receiving condition, or a signal for ordering the rearrangement of the sending order of mail data stored in the mail sender; and

the second mail receiving unit generates the detecting signal supplied to the receiving condition monitoring section, based on a signal input via the input device.

10. An electronic mail system as claimed in claim 1, wherein:

the second mail receiving unit comprises a wireless data processing section for receiving and demodulating the wireless signal from the second communication network, and measuring an error rate of the demodulated digital signal of the mail data according to specific codes included in the digital signal; and

the second mail receiving unit generates the detection signal when the measured error rate of the digital signal becomes larger than a predetermined threshold value.

11. An electronic mail system as claimed in claim 1, wherein the second mail receiving unit comprises a radio wave monitoring section for measuring the power supply voltage of the mail receiver at predetermined intervals, and generates the detection signal when the measured power supply voltage becomes lower than a predetermined threshold value.

12. An electronic mail system as claimed in claim 1, wherein in the rearrangement of the mail data performed by the mail order rearranging section, the order of the mail data is determined according to the degree of importance or urgency of each mail.

13. An electronic mail system as claimed in claim 1, wherein the storage device in the mail sender also stores mail data storage information which indicates a property of each electronic mail.