@inproceedings{Zimm2206:Grade,

title = {Grade to the Edge: How Many Unreliable Nodes Does It Take to Break a Content Delivery Network?},

author = {Sandra {Zimmermann} and Paul {Schwenteck} and Juan A. {Cabrera} and Giang T. {Nguyen} and Frank H. P. {Fitzek}},

year  = {2022},

date = {2022-06-14},

urldate = {2022-06-14},

booktitle = {2022 IEEE 23rd International Symposium on a World of Wireless, Mobile and 

Multimedia Networks (WoWMoM) (WoWMoM 2022)},

address = {Belfast, United Kingdom (Great Britain)},

abstract = {Delivering content from a network via a client-server architecture is 

expensive not only for content owners but also for network operators. 

Moving content closer to the end user is already used in Content Delivery 

Networks (CDN). Mobile Edge Cloud (MEC) enables us to shift the content 

even closer by using the storage of end users. But, due to the large media 

files, storage and transport costs for peers increase significantly. 

Network Coding can reduce these costs. However, peers in CDNs tend to be 

highly fluctuating and often need to be restored, making continuous 

availability of data at the network edge a problem. While for uncoded data, 

individual packets lost due to peer failures can be tracked to determine 

availability, the availability of coded data is currently distinguished 

only in two cases: either there are still enough linearly independent 

packets to decode the file, or there are not. However, we have found that 

the network's combined coded cache loses quality over time due to recovery. 

This quality loss, which we refer to as grade, can be measured by very 

cost-effective monitoring. If the grade falls below a certain limit, we can 

intervene in the network by performing a cache refresh to prevent data 

becoming unavailable preemptively. In this paper, we present the cases in 

which such monitoring is useful, how the grade is calculated, and when a 

cache refresh is necessary. The results show that we can reduce network 

traffic by up to 34 % with minimal storage costs through efficient 

monitoring.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{Zimm2012:Journey,

title = {Journey to MARS: Interplanetary Coding for relieving CDNs},

author = {Sandra {Zimmermann} and Justus {Rischke} and Juan A. {Cabrera} and Frank H. P. {Fitzek}},

year  = {2020},

date = {2020-12-07},

urldate = {2020-12-07},

booktitle = {2020 IEEE Global Communications Conference: Selected Areas in Communications: Cloud \& Fog/Edge Computing, Networking and Storage (Globecom2020 SAC CCNS)},

address = {Taipei, Taiwan},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{Grohmann2020,

title = {SourceShift: Resilient Routing in Highly Dynamic Wireless Mesh Networks},

author = {Andreas I. {Grohmann} and Frank {Gabriel} and Sandra {Zimmermann} and Frank H. P. {Fitzek}},

year  = {2020},

date = {2020-04-05},

booktitle = {2020 IEEE Wireless Communications and Networking Conference (WCNC) (IEEE WCNC 2020)},

address = {Seoul, Korea (South)},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}