IP Fragment Reassembly in Cellular Core Using Encapsulation Headers

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Solution Overview

Problem

In 4G LTE networks, unnecessary IP fragmentation and reassembly within the Evolved Packet Core (EPC) lead to increased computational resources consumption and packet latencies, as well as potential packet loss due to network congestion and reassembly requirements across intermediate routers and switches.

Innovation Solution

Implementing an IP packet fragment reassembly system that determines encapsulation headers to reassemble IP packet fragments before they reach wireless devices, reducing the need for reassembly at these devices and minimizing air interface traffic, using techniques such as setting the More Fragments (MF) bit in inner IP headers and encapsulating packets with GTP headers to indicate fragmentation status.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If IP packet fragmentation is performed on the outer IP packet in the EPC, then the packets can be transmitted through the network core, but unnecessary reassembly and re-fragmentation occurs multiple times increasing computational resources consumption and packet latencies

Engineering Contradiction:

Improvepacket transmission speedVSAvoidpacket latency

Core Design Contradiction:

SpeedVSLoss of time

Solution Approach 1:

The patent applies preliminary action by performing IP packet reassembly at the P-GW before packets are forwarded through the EPC network core. This advance reassembly prevents multiple subsequent reassembly and re-fragmentation operations that would otherwise occur at intermediate routers and switches, thereby reducing computational overhead and packet latency while maintaining proper packet routing through the network

Inventive Principle:

Principle #10Preliminary action

2Adaptability or versatility

If IP packet fragmentation is performed on the outer IP packet, then packets can be routed through the network, but reassembly and re-fragmentation multiple times increases computational resources consumption

Engineering Contradiction:

Improvepacket routing capabilityVSAvoidcomputational resources consumption

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent performs reassembly at the P-GW in advance before packets enter the EPC network core, eliminating the need for intermediate routers and switches to perform computationally intensive reassembly and re-fragmentation operations. This preliminary action maintains full packet routing capability while significantly reducing computational resource consumption across the network

Inventive Principle:

Principle #10Preliminary action

3Reliability

If outer IP packet fragmentation is performed, then packets can be transmitted, but packet loss increases due to network congestion and reassembly requirements at intermediate routers and switches

Engineering Contradiction:

Improvepacket delivery reliabilityVSAvoidpacket loss

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent performs reassembly at the P-GW before packets are transmitted through the EPC network core. By completing reassembly in advance, the patent eliminates the vulnerability of fragmented packets to loss at intermediate routers and switches, particularly during network congestion when fragmented packets may be dropped. This preliminary reassembly action significantly improves packet delivery reliability

Inventive Principle:

Principle #10Preliminary action

4Productivity

If IP packet fragments are transmitted to wireless devices, then devices can receive data, but processing burden increases at the wireless devices

Engineering Contradiction:

Improvedata delivery efficiencyVSAvoiddevice processing ease

Core Design Contradiction:

ProductivityVSEase of operation

Solution Approach 1:

The patent performs reassembly at the P-GW before packets are transmitted to wireless devices via the air interface. This preliminary reassembly action ensures that complete IP packets are delivered to wireless devices rather than fragments, eliminating the need for devices to perform complex reassembly operations and significantly reducing their processing burden while maintaining data delivery efficiency

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS9019990B2Using encapsulation headers to indicate internet protocol packet fragmentation in cellular networks

Publication Date: 2015.04.28 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

A method of an aspect is performed in an Internet Protocol (IP) packet fragment reassembly system of a cellular network. The method is one of reassembling IP packet fragments that are destined for wireless devices. The method includes a step of receiving a plurality of encapsulated IP packet fragments. Each of the encapsulated IP packet fragments have an encapsulation header, an outer IP header, and an inner IP header. The method also includes a step of determining that the encapsulation headers indicate that the IP packet fragments are encapsulated. The method further includes a step of reassembling the IP packet fragments into a reassembled IP packet. A more fragments (MF) bit is set in the inner IP header of each, except for a last one, of the IP packet fragments.